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Clark   University 


1889-1899 


Beeennial  Celebration 


^^t? 


Worcester,   Mass. 

Printed  for  the  University 

1899 


my  390/ 


Copyright,  1899, 

Bt  claek  university. 


WorfaoDli  3,3rcss 

J.  S.  Gushing  &  Co.  —  Berwick  &  Smith 

Norwood,  JIasg.  U.  S.  A. 


1^ 

/  0  377 


PREFACE. 

This  volume  is  intended  not  only  to  commemorate  the  Decen- 
nial Anniversary  of  Clark  University,  but  also  to  make  the  Public 
acquainted  with  its  aims  and  ideals,  and  with  the  character,  scope, 
and  amount  of  the  work  it  has  already  done.  Ever  since  it 
opened  its  doors  to  students  it  has  confined  itself  to  truly  post- 
graduate work  in  a  few  departments,  and  has  admitted  such 
students  only  as  gave  promise  of  the  ability  not  only  to  pursue 
the  courses  here  offered  with  advantage  to  themselves,  but  to 
benefit  the  world  by  advancing  science  along  the  lines  here  repre- 
sented. It  has  thus  taken  a  distinct  position  as  a  training  school 
for  college  professors  and  scientific  investigators.  Such  a  policy 
is  conducive  neither  to  large  numbers  of  students  nor  to  popular 
appreciation.  But,  small  as  the  university  is  and  few  as  are  its 
departments,  it  takes  great  satisfaction  in  pointing  to  this  volume 
as,  in  some  sense,  a  record  of  its  work  and  its  methods.  The 
list  of  titles  of  the  publications  of  its  past  and  present  members 
is  a  witness  of  the  quality  and  quantity  of  what  it  has  accom- 
plished. We  believe  that  Clark  University,  opening,  as  it  did, 
at  the  beginning  of  a  new  university  epoch  in  this  country,  has 
had  some  special  influence  in  suggesting  new  lines  of  scientific 
research. 

The  five  foreign  professors  who  took  part  in  the  Decennial 
Celebration  were  selected  as  the  most  eminent  available  scientific 
men  in  their  respective  lines  in  Europe ;  this  was  the  first  visit  of 
each  to  America,  and  four  of  them  came  here  solely  for  this  anni- 


iv  Preface. 

versary.  Their  lectures  are  here  reproduced  in  exteiiso  and  have 
not  been  published  elsewhere.  The  lectures  of  Professors  Picard 
and  Boltzraann  are  given  in  the  languages  in  which  they  were 
delivered,  and  those  of  Professors  Ramon  y  Cajal,  Mosso,  and 
Forel  in  translations  made  by  members  of  the  Faculty  and  revised 
by  representatives  of  the  departments  to  which  they  severally 
belong.  For  these  laborious  services  the  editors  desire  to  extend 
their  very  particular  thanks  to  the  individuals  who  have  rendered 
them. 

The  reports  of  departments  were  prepared  especially  for  this 
occasion,  and  include  not  only  an  account  of  the  work  actually 
done  during  the  decade,  but  also  a  statement  by  the  officer  in 
charge  of  each  department  of  its  aims  and  ideals  and  the  lines 
along  which  it  hopes  to  advance.  The  responsibility  for  the 
content  and  form  of  each  report  rests  with  the  individual  in 
whose  name  it  is  published ;  all  modifications  by  the  editors  hav- 
ing been  made  in  the  form  of  suggestions  to  the  writers  and 
adopted  only  with  their  consent.  It  is  perhaps  unnecessary  to 
say  that  no  attempt  has  been  made  to  secure  uniformity  in  the 
various  articles,  excepting  in  the  titles  and  in  minor  details  of 
arrangement. 

The  editors  extend  their  hearty  thanks  to  the  authors  of  the 
several  portions  of  the  volume  for  their  cordial  cooperation  and 
for  the  friendly  spirit  in  which  suggestions  have  been  received, 
and  to  all  members  of  the  Faculty  for  assistance  in  reading  the 
proof-sheets. 

WILLIAM  E.  STORY, 
LOUIS  N.  WILSON, 

Editors. 


TABLE    OF   CONTEK'TS 

PAGE 

HISTORICAL   SKETCH 1 

THE   DECENNIAL   CELEBRATION 13 

EXTRACTS   FROM   CONGRATULATORY  LETTERS        ...      25 

DECENNIAL   ADDRESS 45 

By  G.  Stanley  Hall,  President  of  the  University. 

EEPORTS   OF   DEPARTMENTS 

THE  DEPARTMENT   OF  MATHEMATICS 61 

By  William  Edward  Story. 

THE   DEPARTMENT   OF   PHYSICS 85 

By  Arthur  Gordon  Webster. 

THE   DEPARTMENT   OF   BIOLOGY 99 

By  Clifton  F.  Hodge. 

THE   DEPARTMENT   OF  PSYCHOLOGY 119 

General  Psychology 122 

By  Edmund  C.  Sanford. 

Psycho-Pathology 144 

By  Adolf  Meyer. 

Anthropology 148 

By  Alexander  F.  Chamberlain. 

Pedagogy 161 

By  William  H.  Burnham. 

Philosophy 177 

By  G.  Stanley  Hall. 

THE   LIBRARY 187 

By  Louis  N.  Wilson. 

REPORT   OF  THE   TREASURER         .......    199 

By  Thomas  H.  Gage. 

V 


vi  Table  of  Contents 


SCIENTIFIC    LECTUEES 

DELIVERED   IN   CONNECTION   WITH   THE 
DECENNIAL   CELEBRATION 

PAGE 

JSmile  Picard,  Professor  of  Mathematics  at  the  University  of  Paris. 

1.  Sur  I'Extension  de  quelques  Notions  Mathematiques,  et  en  parti- 

culier  de  I'Idee  de  Fonction  depuis  un  Siecle     ....     207 

2.  Quelques  Vues  Generales  sur  la  Theorie  des  ifiquations  Differentielles     224 

3.  Sur  la  Theorie  des  Fonctions  Analytiques  et  sur  quelques  Fonc- 

tions  Speciales 241 

LuDWiG  BoLTZMANx,  Professor  of  TJieoretical  Physics  at  the  University  of 
Vienna. 
Ueber   die   Grundprineipien   und   Grundgleichungen  der  Mechanik. 

(Four  Lectures) 261 

Santiago  Ramon  y  Cajal,  Professor  of  Histology  and  Rector  of  the 
University  of  Madrid. 

1.  Comparative  Study  of  the  Sensory  Areas  of  the  Human  Cortex     .     311 

2.  Layer  of  the  Large  Stellate  Cells 336 

3.  The  Sensori-Motor  Cortex 360 

Angelo  Mosso,  Professor  of  Physiology  and  Rector  of  the   University  of 
Turin. 

1.  Psychic  Processes  and  Muscular  Exercise 383 

2.  The  Mechanism  of  the  Emotions 396 

August  Forel,  Late  Professor  of  Psychiatry  at  the  University  of  Ziirich 
and  Director  of  the  Burghdlzli  Asylum. 

1.  Hypnotism  and  Cerebral  Activity 409 

2.  A  Sketch  of  the  Biology  of  Ants 433 

DEGREES   CONFERRED,   1889-1899 453 

TITLES   OF  PUBLISHED   PAPERS 459 

SPECIAL   STUDENTS 565 


HISTORICAL   SKETCH. 


HISTOEICAL   SKETCH. 

/  (2?  (i*  3  (fi 

Clark  University  was  founded  by  the  munificence  of  Jonas  G.  Clark, 
a  native  of  Worcester  County,  wliose  plans,  conceived  more  than  twenty 
years  before,  had  gradually  grown  with  his  fortune.  His  affairs  had  been 
so  arranged  as  to  allow  long  intervals  for  travel  and  study.  During 
eight  years  thus  spent,  the  leading  foreign  institutions  of  learning,  old 
and  new,  were  visited,  and  their  records  gathered  and  read.  These 
studies  centred  about  the  means  by  which  the  highest  culture  of  one 
generation  is  best  transmitted  to  the  ablest  youths  of  the  next,  and 
especially  about  the  external  conditions  most  favorable  for  increasing 
the  sum  of  human  knowledge.  To  the  improvement  of  these  means  and 
the  enlargement  of  these  conditions,  the  new  University  was  devoted. 

It  was  the  strong  and  express  desire  of  the  founder  that  the  highest 

possible  academic   standards  be  here   forever   maintained ;    that   special 

opportunities  and  inducements  be  offered  to  research  ;  that  to  tliis  end  the 

K     instructors  be  not  overburdened  with  teaching  and  examinations  ;  that 

^     all  available  experience,  both  of  older  countries  and  our  own,  be  freely 

utilized ;  and  that  new  measures,  and  even  innovations,  if  really  helpful 

\^    to  the  highest  needs  of  modern  science  and  culture,  be   no  less   freely 

VJ    adopted  ;  in  fine,  that  the  great  opportunities  of  a  new  foundation  in  this 

land  and  age  be  diligently  explored  and  improved. 

He  chose  Worcester  as  the  seat  of  the  new  foundation  after  mature 
deliberation,  —  first. 

Because  its  location  is  central  among  the  best  colleges  of  the  East,  and 
by  supplementing  rather  than  duplicating  their  work,  he  hoped  to  ad- 
vance all  their  interests  and  to  secure  their  good  will  and  active  support, 
that  together  they  might  take  further  steps  in  the  development  of 
superior  education  in  New  England  ;    and  secondly, 

Because  he  believed  the  culture  of  this  city  would  insure  that  en- 
lightened public  opinion  indispensable  in  maintaining  these  educational 


2  Historical  Sketch. 

standards  at  their  highest,  and  that  its  wealth  would  insure  the  perpetual 
increase  of  revenue  required  by  the  rapid  progress  of  science. 

As  the  first  positive  step  toward  the  realization  of  these  long-formed 
plans,  Mr.  Clark  invited  the  following  gentlemen  to  constitute  with 
himself  a  Board  of  Trustees  :  —  . 

Stephen-  Salisbury,  A.B.,  Harvard,  1856;  Universities  of  Paris  and  Berlin, 

1856-58;  LL.B.,  Harvard,  1861;  President  Antiquarian  Society  since  1887; 

State  Senator,  1892-95. 
Charles  Devens,  A.B.,  Harvard,  1838 ;  LL.B.,  Harvard,  1840 ;  Major-General, 

1863 ;   Associate  Justice  of   the  Massachusetts    Superior  Court,  1867-73 ; 

Associate  Justice  of  the  Massachusetts  Supreme  Judicial  Court,  1873-77, 

and  again,   1881-91 ;    Attorney-General  of  the   United   States,   1877-81 ; 

LL.D.,  Columbia  and  Harvard,  1877;  Died  January  7,  1891. 
George  F.  Hoar,  A.B.,  Harvard,  1846 ;  LL.B.,  Harvard,  1849 ;  United  States 

House  of  Eepresentatives,  1869-77 ;  Member  Electoral  Commission,  1876 ; 

United  States  Senate  since  1877 ;  Chairman  of  Judiciary  Committee,  1891 — ; 

LL.D.,  William  and  Mary,  Amherst,  Harvard,  and  Yale. 
William  W.  Kice,  A.B.,  Bowdoin,  1846;  admitted  to  Bar,  1854;  United  States 

House  of  Eepresentatives,  1876-86 ;  LL.D.,  Bowdoin,  1886.     Died  March  1, 

1896. 
Joseph  Sargekt,  A.B.,  Harvard,  1834 ;  M.D.,  Harvard,  1837 ;  London  and  Paris 

Hospitals,  1838-40.     Died  October  13,  1888. 
JoHK  D.  WASHBUR^^,  A.B.,  Harvard,  1853;  LL.B.,  Harvard,  1856;  Eepresenta- 

tive,  1876-79 ;  State  Senate,  1884 ;  United  States  Minister  to  Switzerland, 

1889-92. 
Frank   P.   Goulding,  A.B.,  Dartmouth,  1863;   Harvard   Law   School,  1866; 

City  Solicitor,  1881-93. 
George   Swan,  A.B.,   Amherst,    1847 ;   admitted  to   Bar,   1848 ;    Member   of 

Worcester  School  Board,  1879-90 ;   Chairman  of  High  School  Committee, 

1887-90. 

The  following  gentlemen  have  been  added  to  the  Board  since  to  fill 
vacancies  caused  by  death.     In  place  of  Dr.  Sargent  :  — 

Edward  Cowles,  A.B.,  Dartmouth,  1859;  M.D.,  Dartmouth,  1862,  and  Col- 
lege of  Physicians  and  Surgeons,  N.  Y.,  1863 ;  Assistant  Surgeon,  U.  S.  A., 
1863-72 ;  Eesident  Physician  and  Superintendent  Boston  City  Hospital, 
1872-79 ;  Medical  Superintendent  McLean  Asylum  smce  1879 ;  Professor  of 
Mental  Diseases,  Dartmouth  IMedical  School,  since  1885 ;  Clinical  Instructor 
in  Mental  Diseases,  Harvard  Medical  School,  since  1888. 

In  place  of  General  Devens: 

Thomas  H.  Gage,  M.D.,  Harvard,  1852;  President  Massachusetts  Medical 
Society,  1886-88. 


Historical  Sketch.  3 

On  petition  of  this  Board,  the  Legislature  passed  the  following 

Act  of  Incorporation,     Chapter  133. 

commonwealth  of  massachusetts,  in  the  year  one  thousand  eight  hun- 
dred and  eighty-seven.  an  act  to  incorporate  the  trustees  of 
clark  university  in  worcester. 

Be  it  enacted  by  the  Senate  and  House  of  Kepresentatives  in  General  Court 
assembled,  and  by  authority  of  the  same,  as  follows  :  — 

Section  1.  Jonas  G.  Clark,  Stephen  Salisbury,  Charles  Devens,  George  F. 
Hoar,  William  W.  Rice,  Joseph  Sargent,  John  D.  Washburn,  Frank  P.  Gould- 
ing  and  George  Swan,  all  of  the  city  of  Worcester,  in  the  Commonwealth  of 
Massachusetts,  and  their  successors,  are  hereby  made  a  corporation  by  the  name 
of  the  Trustees  of  Clark  University,  to  be  located  in  said  Worcester,  for  the 
purpose  of  establishing  and  maintaining  in  said  city  of  Worcester  an  institu- 
tion for  the  promotion  of  education  and  investigation  in  science,  literature  and 
art,  to  be  called  Clark  University. 

Section  2.  Said  corporation  may  receive  and  hold  real  or  personal  estate 
by  gift,  grant,  devise,  bequest  or  otherwise,  for  the  purpose  aforesaid,  and  shall 
have  all  the  rights,  privileges,  immunities,  and  powers,  including  the  conferring 
of  degrees,  which  similar  incorporated  institutions  have  in  this  Commonwealth. 

Section  3.  Said  corporation  shall  have  the  power  to  organize  said  Univer- 
sity in  all  its  departments,  to  manage  and  control  the  same,  to  appoint  its 
officers,  who  shall  not  be  members  of  said  corporation,  and  to  fix  their  com- 
pensation and  their  tenure  of  office ;  and  said  corporation  may  provide  for  the 
appointment  of  an  advisory  board  and  for  the  election  by  the  Alumni  of  said 
University  to  fill  any  vacancies  in  said  board. 

Section  4.  The  number  of  members  of  said  corporation  shall  not  be  less 
than  seven  nor  more  than  nine,  and  any  vacancy  therein  may  be  filled  by  the 
remaining  members  at  a  meeting  duly  called  and  notified  therefor ;  and  when  any 
member  thereof  shall,  by  reason  of  infirmity  or  otherwise,  become  incapable,  in 
the  judgment  of  the  remaining  members,  of  discharging  the  duties  of  his  office, 
or  shall  neglect  or  refuse  to  perform  the  same,  he  may  be  removed  and  another 
be  elected  to  fill  his  place,  by  the  remaining  members,  at  a  meeting  duly  called 
and  notified  for  that  purpose. 

Section  5.     This  Act  shall  take  effect  upon  its  passage. 

House  of  Eepresentatives,  March  30,  1887,  Passed  to  be  Enacted. 

Charles  J.  Noyes,  Speaker. 
Senate,  March  31,  1887,  Passed  to  be  Enacted. 

Halsey  J.  BoARDMAN,  President. 

During  the  previous  five  years,  Mr.  Clark  had  gradually  acquired  a 
tract  of  land,  comprising  over  eight  acres,  located  on  Main  Street,  about 


4  Historical  Sketch. 

a  mile  from  the  heart  of  the  city,  with  additional  tracts  near  by.  This 
land  has  considerable  elevation  above  that  part  of  the  city,  is  a  watershed 
sloping  to  the  southeast,  insuring  sanitary  excellence  and  a  wide  and 
picturesque  view.  A  park  reservation  of  about  25  acres,  directly  oppo- 
site, has  been  set  apart  by  the  city,  and  named  University  Park. 

Plans  for  a  main  building  were  submitted  to  the  Board  by  Mr.  Clark, 
which  were  approved,  and  its  erection  was  at  once  begun.  The  corner- 
stone was  laid  with  impressive  ceremonies,  October  22,  1887.  This  build- 
ing is  plain,  substantial,  and  well  appointed,  204  x  114  feet,  four  stories  high 
and  five  in  the  centre,  with  superior  facilities  for  heating,  lighting,  and 
ventilation,  and  has  been  constructed  of  brick  and  granite,  and  finished 
throughout  in  oak.  On  the  whole  it  is  a  model  of  stability  and  solid  work- 
manship. It  contains  a  total  of  90  rooms,  and  in  its  tower  is  a  clock  with 
three  six-foot  illuminated  dials,  which  was  presented  by  the  citizens  of 
Worcester.  The  elevations  and  ground  plan  are  published,  and  the  heat- 
ing, lighting,  ventilation,  walls,  floors,  etc.,  etc.,  are  described  in  detail 
in  the  Third  Official  Announcement. 

On  April  3,  1888,  G.  Stanley  Hall,  then  a  professor  at  Johns 
Hopkins  University,  was  invited  to  the  presidency.  The  ofiicial  letter 
conveying  the  invitation  to  the  president  contained  the  following  well-con- 
sidered and  significant  expression  of  the  spirit  animating  the  trustees  :  — 

"  They  desire  to  impose  on  you  no  trammels ;  they  have  no  friends  for  whom 
they  wish  to  provide  at  the  expense  of  the  interests  of  the  institution ;  no  pet 
theories  to  press  upon  you  in  derogation  of  your  judgment ;  no  sectarian  tests 
to  apply ;  no  guarantees  to  require,  save  such  as  are  implied  by  your  acceptance 
of  this  trust.  Their  single  desire  is  to  fit  men  for  the  highest  duties  of  life, 
and  to  that  end,  that  this  institution,  in  whatever  branches  of  sound  learning 
it  may  find  itseK  engaged,  may  be  a  leader  and  a  light." 

This  invitation  was  accepted  May  1,  and  the  president  was  at  once 
granted  one  year's  leave  of  absence,  with  full  salary,  to  visit  universities 
in  Europe.  This  year  was  diligently  improved  in  gathering  educational 
literature  and  collecting  information  and  advice  from  leading  authorities. 
Many  reports  based  upon  this  work  have  already  been  made  in  the  Peda- 
gogical Seminary  and  more  are  in  course  of  preparation. 

During  the  absence  of  the  president  a  Chemical  Laboratory  was  begun. 
This  building  in  its  main  body  has  three  stories,  in  its  eastern  wing  four, 
in  its  southwestern  two.  It  contains  68  rooms.  The  outer  walls  are 
2  feet  in  thickness  and  the  partition  walls  from  12  to  16  inches.     All  par- 


Historical  Sketch.  5 

titions  are  of  brick,  so  that  the  building  is  nearly  fireproof.  The  two 
large  laboratories  are  24  x  58  feet  and  22  feet  high.  This  building  is 
also  described  with  plans  in  the  Third  Official  Annou7icement. 

The  opening  exercises  were  held  in  a  hall  of  the  University,  seating 
1500  people,  on  Wednesday,  October  2,  1889.  The  late  General  Charles 
Devens  presided,  and  made  an  opening  address.  Addresses  were  made 
by  Senator  George  F.  Hoar  and  the  president.  The  founder  of  the 
University  stated  his  purpose  as  follows  :  — 

"  When  we  first  entered  upon  our  work  it  was  with  a  well-defined  plan  and 
purpose,  in  which  plan  and  purpose  we  have  steadily  persevered,  turning 
neither  to  the  right  nor  to  the  left.  We  have  wrought  upon  no  vague  concep- 
tions nor  suffered  ourselves  to  be  borne  upon  the  fluctuating  and  unstable 
current  of  public  opinion  or  public  suggestions.  We  started  upon  our  career 
with  the  determinate  view  of  giving  to  the  public  all  the  benefits  and  advan- 
tages of  a  university,  comprehending  full  well  what  that  implies,  and  feeling 
the  full  force  of  the  general  understanding,  that  a  university  must,  to  a  large 
degree,  be  a  creation  of  time  and  experience.  We  have,  however,  boldly 
assumed  as  the  foundation  of  our  institution  the  principles,  the  tests,  and  the 
responsibilities  of  universities  as  they  are  everywhere  recognized  —  but  with- 
out making  any  claim  for  the  prestige  or  flavor  which  age  imparts  to  all  things. 
It  has  therefore  been  our  purpose  to  lay  our  foundation  broad  and  strong  and 
deep.  In  this  we  must  necessarily  lack  the  simple  element  of  years.  We 
have  what  we  believe  to  be  more  valuable  —  the  vast  storehouse  of  the  knowl- 
edge and  learning  which  has  been  accumulating  for  the  centuries  that  have 
gone  before  us,  availing  ourselves  of  the  privilege  of  drawing  from  this  source, 
open  to  all  alike.  We  propose  to  go  on  to  further  and  higher  achievements. 
We  propose  to  put  into  the  hands  of  those  who  are  members  of  the  University, 
engaged  in  its  several  departments,  every  facility  which  money  can  command 
—  to  the  extent  of  our  ability  —  in  the  way  of  apparatus  and  appliances  that 
can  in  any  way  promote  our  object  in  this  direction.  To  our  present  depart- 
ments we  propose  to  add  others  from  time  to  time,  as  our  means  shall  warrant 
and  the  exigencies  of  the  University  shall  seem  to  demand,  always  taking  those 
first  whose  domain  lies  nearest  to  those  already  established,  until  the  full 
scope  and  purpose  of  the  University  shall  have  been  accomplished. 

"  These  benefits  and  advantages  thus  briefly  outlined,  we  propose  placing  at 
the  service  of  those  who  from  time  to  time  seek,  in  good  faith  and  honesty  of 
purpose,  to  pursue  the  study  of  science  in  its  purity,  and  to  engage  in  scientific 
research  and  investigation  —  to  such  they  are  offered  as  far  as  possible  free 
from  all  trammels  and  hindrances,  without  any  religious,  political,  or  social 
tests.  All  that  will  be  required  of  any  applicant  will  be  evidence,  disclosed 
by  examinations  or  otherwise,  that  his  attainments  are  such  as  to  qualify  him 
for  the  position  that  he  seeks." 


6  Historical  Sketch. 

After  careful  consideration  it  was  decided  to  begin  with  graduate 
work  only  and  in  the  following  five  departments  : 

I.  Mathematics. 

II,  Physics,  Experimental  and  Theoretical. 

III.  Chemistry,  Organic,  Inorganic,  Physical,  and  Crystallography. 

IV.  Biology,  including  Anatomy,  Physiology,  and  Paleontology. 

V.   Psychology,  including  Neurology,  Anthropology,  and  Education. 

Mathematics  is  sometimes  called  the  queen  of  all  the  sciences.  As 
the  latter  become  exact,  they  approximate  it,  and  are  fructified  by  its 
spirit  and  its  methods.  Its  antiquity,  its  disciplinary  value,  its  rapid 
and  recent  development,  make  it  obviously  indispensable.  Physics  is 
the  field  of  the  most  immediate  application  of  mathematics,  and  deals 
with  the  fundamental  forces  of  the  material  universe,  —  heat,  sound, 
light,  electricity,  —  and  the  underlying  problems  of  form  and  motion 
generally,  with  their  vast  field  of  application  in  such  sciences  as  astronomy 
and  dynamic  geology.  Chemistry,  with  its  great  and  sudden  development, 
revealino-  marvellous  order  and  harmony  in  the  constitution  of  matter, 
is  rapidly  extending  its  dominion  over  industrial  processes.  Biology, 
which  seeks  to  fathom  the  laws  of  life,  death,  reproduction,  and  disease, 
that  underlies  all  the  medical  sciences,  in  its  broader  aspects  has  taught 
man  in  recent  decades  far  more  concerning  his  origin  and  nature  than  all 
that  was  known  before.  Psychology,  or  the  study  of  man's  faculties 
and  their  education,  is  a  new  field  into  which  all  the  sciences  are  bringing 
so  many  of  their  richest  and  best  ideas,  which  is  now  so  full  of  promise 
for  the  life  of  man. 

A  sub-department  of  Education  was  established  in  1892,  and  the 
department  of  Chemistry  was  temporarily  discontinued  in  1894. 

To  express  more  explicitly  the  character  and  policy  of  the  institution, 
the  Trustees  voted  to  approve  and  publish  the  following  statement  :  — 

"  As  the  work  of  the  University  increases,  its  settled  policy  shall  be  always 
to  first  strengthen  departments  already  established,  until  they  are  as  thorough, 
as  advanced,  as  special,  and  as  efficient  as  possible,  before  proceeding  to  the 
establishment  of  new  ones. 

"When  this  is  done  and  new  departments  are  established,  those  shall  always 
be  chosen  first  which  are  scientifically  most  closely  related  to  departments 
already  established ;  that  the  body  of  sciences  here  represented  may  be  kept 
vigorous  and  compact,  and  that  the  strength  of  the  University  may  always 
rest,  not  upon  the  number  of  subjects,  nor  the  breadth  or  length  of  its  cur- 
riculum, but  upon  its  thoroughness  and  its  unity. 


Historical  Sketch.  7 

"  This  shall  in  no  wise  hinder  the  establishment,  by  other  donors  than  the 
founder,  of  other  and  more  independent  departments  if  approved  by  the 
Trustees. 

"  While  ability  in  teaching  shall  be  held  of  great  importance,  the  leading 
consideration  in  all  engagements,  reappointments,  and  promotions  shall  be  the 
quality  and  quantity  of  successful  investigation." 

By  thus  limiting  the  work  of  the  University  in  the  beginning  to 
five  departments,  it  appeals  only  to  advanced  men  who  desire  to  specialize 
in  one  or  more  of  these  fundamental  sciences,  leaving  college  students 
who  require  a  larger  range  of  studies,  as  well  as  those  who  desire  to 
devote  themselves  to  language  and  literature,  historical,  technical,  or  pro- 
fessional studies,  to  go  elsewhere.  Hence  our  work  must  be  post- 
graduate. This  requires  the  best  professors  and  apparatus,  more  books 
and  journals,  and  necessitates  a  system  of  fellowships,  scholarships,  and 
provisions  for  original  research.  It  thus  becomes  a  training-school  for 
professors.  This  is  the  most  expensive  of  all  educational  work,  seeks 
the  fewest  but  the  best  men  from  the  widest  area,  and  to  succeed  must 
be  helpful  in  elevating  the  academic  standards  of  the  country  to  a  higher 
plane.  It  requires  the  highest  degree  of  wisdom  and  foresight  on  the 
part  of  the  Founder  and  the  Trustees,  and  possibly  some  sacrifices  of 
local  sjrmpathy  and  support  at  first,  till  the  nature  of  the  work  is  well 
understood.  It  requires  the  greatest  effort  and  devotion  to  work  on 
the  part  of  the  Faculty  and  students.  But  the  cause  is  itself  an  inspira- 
tion. It  appeals  to  the  future,  the  country,  and  to  the  world,  and  seeks 
quality  more  than  numbers.  It  is  in  the  current  of  all  the  best  tenden- 
cies in  the  best  lands,  and  is  now  the  ideal  of  perhaps  every  eminent 
man  of  science  everywhere.  The  inauguration  and  steady  maintenance 
of  this  clear  and  simple  policy  gives  the  University  a  reason  for  being, 
and  a  distinct  individuality  it  could  not  otherwise  have,  and  also  a  real 
leadership  in  this  epoch  of  awakening  and  transition,  which  is  the  golden 
time  of  opportunity  for  new  institutions,  and  brings  them  to  the  front. 
Such  a  period  as  the  present  gives  the  latter  even  greater  relative  influ- 
ence and  prominence  than  would  be  possible  in  periods  of  less  public 
interest  in  education.  New  institutions  can  and  should  lead,  set  new 
fashions,  and  be  the  first  upon  the  higher  planes.  Older  institutions 
are  retarded  by  conservatism  and  must  advance  more  slowly,  but 
when  they  move  they  carry  great  momentum.  This  condition  makes 
the   present  a  moment   of    perhaps   unprecedented    opportunity,    which 


8  Historical  Sketch, 

has  been  long  looked  for  and  long  delayed,  and  whicli  renders 
both  funds  and  labor  in  this  field  more  precious  than  they  have 
been,  or  will  be  when  it  is  past.  We  may  all  be  content  if  our  Uni- 
versity can  transmit  to  future  generations  by  means  of  its  organization, 
plan,  and  methods  the  best  and  highest  educational  tendencies  and  move- 
ments now  stirring  the  souls  of  the  best  men  of  the  world,  and  uniting 
men  of  all  lands,  races,  creeds,  and  stations  in  a  larger  if  not  also  a  deeper 
consensus  of  belief  than  history  has  ever  known  before. 

Our  University  does  not  draw  its  chief  earnings  from,  or  do  most  of 
its  teaching  for,  undergraduates,  and  our  so-called  graduate  students  do 
not  take  undergraduate  courses.  This  makes  the  proportion  of  expendi- 
ture to  income  very  high  here,  and  indeed  we  can  admit  and  do  justice 
to  but  comparatively  few  students.  Most  of  those  who  come  here  have 
spent  one  or  more  years  after  graduation  in  teaching,  or  in  study  in 
Europe  or  elsewhere.  Most  of  those  who  have  been  members  here  have 
already  obtained  professorships  or  other  academic  positions  elsewhere. 
The  proportion  of  such  is  hardly  excelled  by  the  Ecole  Normale  of  Paris, 
the  special  function  of  which  is  to  train  professors  from  other  collegiate 
institutions.  Every  student  who  obtains  original  results  is  exjDected  to 
present  them  in  the  form  of  lectures  to  his  department,  and  thus  to 
acquire  experience  in  teaching  under  criticism.  The  work  of  the  educa- 
tional department  deals  with  problems  and  history  of  higher  educational 
institutions,  and  is  adaj^ted  to  all  the  body  of  fellows  and  scholars,  and 
seeks  to  increase  the  efficiency  of  every  man  both  as  a  teacher  of  his  own 
specialty  and  in  general  helpfulness  to  the  institution  with  which  he  is  to 
be  connected. 

Since  the  opening  of  the  University  not  less  than  five  hundred  books, 
memoirs,  theses,  or  articles  ^  have  been  published  by  members  of  the  Uni- 
versity, which  attempt  to  make  additions  to  the  sum  of  human  knowledge. 
These  contributions  are  of  very  different  orders  of  value,  but  together  they 
constitute  a  body  of  knowledge  in  which  the  institution  takes  special  pride. 
Every  member  of  the  University  is  expected  to  make  at  least  one  long  and 
serious  effort  of  this  kind.  Indeed,  had  its  publications  no  value  as  contri- 
butions to  knowledge,  its  educational  value  is  the  highest  for  mature  men. 
Such  effort  gets  minds  into  independent  action,  gives  a  sense  of  authority 
and  of  true  mental  freedom,  which  no  amount  of  acquisition  can  bring.  It 
brings  out  new  powers  of  mind  and  of  will,  and,  while  one  of  the  chief 

1  A  list  of  these  publications  will  be  found  at  the  end  of  this  volume. 


Historical  Sketch.  9 

marks  by  which  true  University  work  is  distinguished  from  that  of  lower 
grades,  is  in  the  line  of  all  present  tendencies  to  place  doing  above  know- 
ing from  the  kindergarten  up.  Work  that  is  published  enlarges  the 
sphere  of  interests  of  the  author,  subjects  him  to  the  higher  test  of  being 
judged  by  his  peers  elsewhere,  and  brings  in  the  potent  and  salutary 
stimulus  of  wider  competition.  This  baptism  of  ink  has  often  marked  a 
new  birth  of  ideals  and  ability  in  young  men.  Modern  as  distinct  from 
earlier  culture  culminates  in  the  man-making  training  of  will  and  judg- 
ment thus  given.  Such  work,  too,  gives  teaching  a  new  power  and  zest. 
Instruction  to  a  fit  few  by  an  investigator  who  stands  on  the  frontier  and 
has  once  felt  the  light  and  heat  in  which  discovery  is  wrought  out  is 
inspiring,  and  is  very  different  from  information  imparted  at  lower  levels 
by  teachers  further  removed  from  the  work  of  discovery  and  creation. 

Clark  University  is  exclusively  what  is  called  in  Europe  a  Philo- 
sophical Faculty,  or  a  part  of  one  so  far  as  yet  developed,  devoted  to  a 
group  of  the  pure  sciences  which  underlie  technology  and  medicine,  but 
does  not  yet  apply  its  work  to  these  professional  fields.  These  or  a 
college  course  could  be  added  with  relatively  less  expense.  Our 
method  has  brought  us  face  to  face  with  many  new  problems.  Our 
efforts  at  solving  some  of  these  are  described  in  the  department  reports 
which  follow.  Like  all  new  institutions,  we  have  not  entirely  escaped 
trials,  but  we  trust  we  have  learned  their  lesson,  and  shall  be  the  better 
and  stronger  for  them.  Instead  of  dispersing  our  energies  in  university 
extensions,  we  have  followed  the  opposite  course  of  university  concentra- 
tion, like  the  Ecole  Pratique  of  France.  Accepting  the  plain  lesson  of 
history  that  the  best  educational  influences  work  from  above  downward, 
that  universities  create  the  material  of  culture,  while  lower  institutions 
are  the  canals  for  its  distribution,  we  have  sought  aid  for  the  latter  work 
by  an  educational  sub-department  and  summer  school.  We  are  not  like 
the  Smithsonian  Institute,  the  Naples  school,  the  Meichsanstalt,  academies 
of  science,  etc.,  devoted  solely  to  research,  but  have  to  make  our  lectures 
more  condensed  and  fewer  than  usual,  because  addressed  to  advanced 
men,  and  to  devise  ways  of  making  seminary  and  laboratory,  two  of  the 
noblest  words  in  the  vocabulary  of  higher  education,  more  effective.  We 
have  tried  to  effect  systematic  exchanges  with  foreign  institutions,  —  and 
our  library  has  profited  largely  from  this  source,  —  and  have  sought  by 
all  the  above  means  to  aid  in  giving  to  universities  and  to  professors  the 
position  due  them  in  a  time  when  sciences  have  come  to  underlie  all  the 


10  Historical  Sketch. 

arts  of  peace  and  war,  and  when  the  world,  in  all  its  activities,  industry 
and  trade,  professions,  legislation,  is  coming  to  be  more  and  more  con- 
trolled by  experts,  thus  trained  to  the  frontier  of  their  specialties. 

The  degree  of  Doctor  of  Philosophy  has  been  conferred  upon  can- 
didates, whose  names,  together  with  the  dates  of  their  final  examinations 
and  the  subjects  of  their  dissertations,  are  given  later  in  this  volume. 

Other  historical  facts  are  given  in  the  President's  Address  at  the 
Decennial  Celebration. 


REQUIREMENTS   FOR   THE   DEGREE   OF   DOCTOR   OF 

PHILOSOPHY. 

At  least  two  years,  and  in  most  cases  three  years,  of  graduate  work 
will  be  necessary  for  this  degree.  Examinations  for  it,  however,  may 
be  taken  at  any  time  during  the  academic  year  when,  in  the  judgment 
of  the  University  authorities,  the  candidate  is  prepared.  A  prearranged 
period  of  serious  work  at  the  University  itself  is  indispensable. 

For  this  degree  the  first  requirement  is  a  dissertation  upon  an 
approved  subject,  to  which  it  must  be  an  original  contribution  of  value. 
To  this  capital  importance  is  attached.  It  must  be  reported  on  in 
writing  by  the  chief  instructor  before  the  examination,  printed  at  the 
expense  of  the  candidate,  and  at  least  one  hundred  copies  given  to 
the  University.  In  case,  however,  of  dissertations  of  very  unusual 
length,  or  containing  very  expensive  plates,  the  Faculty  shall  have 
power,  at  the  request  of  the  candidate,  to  reduce  this  number  of  presen- 
tation copies  to  fifty. 

Such  formal  or  informal  tests  as  the  Faculty  shall  determine,  shall 
mark  the  acceptance  of  each  student  or  fellow  as  a  candidate  for  this 
degree.  One  object  of  this  preliminary  test  shall  be  to  insure  a  good 
reading  knowledge  of  French  and  German.  Such  formal  candidature 
shall  precede  by  at  least  one  academic  year  the  examination  itself. 
(See  special  rules  below.) 

The  fee  for  the  doctor's  degree  is  $25,  and  in  every  case  it  must 
be  paid  and  the  presentation  copies  of  the  dissertation  must  be  in  the 
hands  of  the  Librarian  before  the  diploma  is  given.  In  exceptional 
cases,  however,  and  by  special  action  of  the  Faculty,  the  ceremony 
of   promotion   may  precede  the   presentation   of   the   printed   copies  of 


Historical  Sketch,  11 

the  dissertation.  The  latter,  however,  must  always  precede  the  actual 
presentation  of  the  diploma. 

An  oral  but  not  a  written  examination  is  required  upon  at  least 
one  minor  subject  in  addition  to  the  major,  before  an  examination 
jury  composed  of  at  least  four  members,  including  the  head  of  the 
department  and  the  President  of  the  University,  who  is  authorized 
to  invite  any  person  from  within  or  without  the  University  to  be 
present  and  to  ask  questions.  The  jury  shall  report  the  results  of 
the  examination  to  the  Faculty,  which,  if  it  is  also  satisfied,  may 
recommend  the  candidate  for  the  degree. 

For  the  bestowal  of  this  degree,  the  approbation  of  the  Board  of 
Trustees  must  in  each  case  be  obtained.  They  desire  that  the  standard 
of  requirements  for  it  be  kept  the  highest  practicable,  that  it  be  reserved 
for  men  of  superior  ability  and  attainment  only,  and  that  its  value 
here  be  never  suffered  to  depreciate. 

It  is  to  the  needs  of  these  students  that  the  lectures,  seminaries, 
laboratories,  collections  of  books,  apparatus,  etc.,  are  specially  shaped, 
and  no  pains  will  be  spared  to  afford  them  every  needed  stimulus 
and  opportunity.  It  is  for  them  that  the  Fellowships  and  Scholarships 
are  primarily  intended,  although  any  of  these  honors  may  be  awarded 
to  others. 

SPECIAL  RULES. 

I.  Residence.  —  No  candidate  shall  receive  the  degree  of  Doctor  of 
Philosophy  without  at  least  one  year's  previous  residence. 

II.  Candidature  for  the  Doctors  Degree. — Every  applicant  for  the 
doctor's  degree  shall  fill  out  before  October  15th  the  regular  appli- 
cation blank  provided  at  the  office.  This  schedule  shall  be  submitted 
to  the  head  of  the  department  and  the  instructor  in  the  major  subject. 
Before  affixing  their  signatures  they  shall  satisfy  themselves,  in  such 
manner  as  they  may  desire,  as  to  the  fitness  of  the  applicant. 

III.  When  countersigned,  this  schedule  shall  be  filed  with  the 
President,  who  will  appoint  an  examiner  to  serve  with  a  representative 
of  the  major  subject  as  a  committee  to  determine  the  proficiency  of 
the  applicant  in  French  and  German. 

IV.  In  case  of  a  favorable  report  by  this  committee  the  applicant 
shall  be  a  regular  candidate  for  the  degree. 

V.  Candidates  complying  with  all  preliminary  conditions,  including 


12  Historical  Sketch. 

the  examinations  in  French  and  German,  before  November  1st,  will 
be  allowed  to  proceed  to  the  doctor's  examination  at  any  time  between 
May  15th  following  and  the  end  of  the  academic  year. 

VI.  Dissertation.  —  The  dissertation  must  be  presented  to  the  in- 
structor under  whose  direction  it  was  before  written,  and  reported  upon 
by  him  before  the  final  examination.  In  every  case  the  dissertation  shall 
be  laid  before  the  jury  of  examination,  at  the  time  of  examination,  in  form 
suitable  for  publication.  This  provision  shall  not,  however,  preclude  the 
making  of  such  minor  changes  later  as  the  chief  instructor  may  approve. 

VII.  The  dissertation  shall  be  printed  at  the  expense  of  the  can- 
didate, and  the  required  copies  deposited  with  the  Librarian  within 
one  calendar  year  from  the  1st  of  October  following  the  examination. 
The  candidate  alone  will  be  held  responsible  for  the  fulfilment  of  these 
conditions. 

VIII.  The  favorable  report  of  the  chief  instructor,  filed  in  writing 
with  the  Clerk  of  the  University,  shall  be  a  sufficient  imprimatur  or 
authorization  for  printing  as  a  dissertation.  The  printed  copies  shall 
bear  upon  the  cover  the  statement  of  approval  in  the  following  words, 
over  the  name  of  the  chief  instructor :  — 

A  Dissertation  submitted  to  the  Faculty  of  Clark  University,  Wor- 
cester, Mass.,  in  partial  fulfilment  of  the  requirements  for  the  degree 
of  Doctor  of  Philosophy,  and  accepted  on  the  recommendation  of 
(name   of  the   chief  instructor). 

IX.  Examinations  for  the  Doctor'' s  Degree.  —  The  examinations  for 
the  doctor's  degree  may  be  held  at  any  time  during  the  academic 
year,  provided  that  at  least  one  academic  year  has  elapsed  since  the 
completion  of  the  preliminaries  of  candidature,  except  in  the  case  of 
fulfilment  of  these  conditions  between  the  beginning  of  any  academic 
year  and  November  1st  of  that  year,  to  which  case  Rule  V.  applies. 
The  examinations  shall  be  held  at  such  hours  and  places  as  the  President 
may  appoint. 

X.  Examinations  may  also  be  held  during  the  regular  vacations 
of  the  University,  but  for  these  an  additional  fee  of  five  dollars  to 
each  examiner,  and  the  reasonable  travelling  expenses  of  any  examiners 
who  are  out  of  town,  all  payable  in  advance,  will  be  required. 

XI.  All  these  special  rules  shall  go  into  force  immediately  as  far 
as  practicable,  and  shall  govern  all  applicants  for  degrees  in  the  academic 
year  1899-1900. 


THE   DECENNIAL   CELEBEATION. 


The  work  of  Clark  University  is  so  technical  and  special  that  it  is 
necessarily  more  or  less  withdrawn  from  popular  interest.  It  has  no 
commencements,  and  comes  in  very  little  contact  with  the  public  or  the 
press  in  Worcester,  or  indeed  with  collegiate  institutions  in  other  parts  of 
the  country.  This  is  a  disadvantage  so  far  as  local  or  general  public 
interest  in  its  work  is  concerned,  but  the  fact  that  it  does  not  exercise 
many  of  the  usual  functions  of  a  college  is  also  a  distinct  advantage  to  its 
scientific  work.  The  close  of  the  tenth  year  of  its  existence  presented  an 
opportunity  to  bring  before  the  public,  in  a  simple  way,  befitting  at  once 
its  size  and  its  quality,  a  presentation  of  the  work  it  has  accomplished  in 
the  past  and  of  its  hopes  and  needs  for  the  future.  Early  last  winter  the 
President  began  to  consider  plans  of  marking  this  anniversary,  and,  with 
the  efficient  aid  of  the  Faculty,  they  gradually  took  defuiite  shape.  A 
personal  appeal  was  then  made  to  a  number  of  public-spirited  and  wealthy 
citizens  of  Worcester,  and  the  scheme  was  rendered  feasible  by  the  gen- 
erosity of  the  following  gentlemen,  who  donated  the  sums  affixed  to  their 
names :  — 


Mr.  Stephen  Salisbury,  f  1000 

Mr.  Philip  W.  Moen,  500 

Mr.  Thomas  H.  Dodge,  200 

Mr.  Edward  D.  Thayer,  Jr.,  200 

Mr.  Charles  S.  Barton,  100 

Mr.  John  H.  Goes,  100 

Mr.  Andrew  H.  Green,  100 

Mr.  Arthur  M.  Stone,  100 

John  0.  Marble,  M.D.,  50 


Mr.  C.  Henry  Hutchins,  $500 

Mr.  William  E.  Rice,  500 

Mr.  Orlando  W.  Norcross,  200 

Mr.  Matthew  J.  Whittall,  150 

Mr.  A.  Swan  Brown,  100 

Mr.  Loring  Goes,  100 

Mr.  James  Logan,  100 

Mr.  Joseph  H.  Walker,  100 

Mr.  Frederick  L.  Goes,  25 


Gharles  L.  Nichols,  M.D.,      $25. 
13 


14  Decennial 

It  was  decided  that  the  close  of  the  tenth  academic  year  should  be 
celebrated  (1)  by  courses  of  lectures  delivered  by  distinguished  foreign 
scientific  men,  (2)  by  public  exercises,  and  (3)  by  an  evening  reception. 

A  conference  was  then  held  concerning  the  most  prominent  leaders  in 
Europe  in  branches  especially  cultivated  at  the  University,  and  after  some 
correspondence  the  following  persons  were  invited  to  give  from  two  to 
four  lectures  each :  — 

Emile  Picard,  Professor  of  Mathematics  at  the  University  of  Paris. 

LuDwiG  BoLTZMANN,  Profcssor  of  Theoretical  Physics  at  the  University  of 
Vienna. 

Angelo  Mosso,  Professor  of  Physiology  and  Kector  of  the  University  of  Turin. 

Santiago  Ramon  y  Cajal,  Professor  of  Histology  and  Eector  of  the  Univer- 
sity of  Madrid. 

August  Forel,  late  Professor  of  Psychiatry  at  the  University  of  Zurich  and 
Director  of  the  Burgholzli  Asylum. 

Under  the  direction  of  a  committee  consisting  of  Assistant  Professor 
A.  G.  Webster  and  Professor  W.  E.  Story,  the  following  forms  of 
invitation  to  the  various  parts  of  the  programme  were  prepared:  — 


Celebration.  15 


^^^ 


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:^^^:^^^^^=:^^^^^^. 


16 


Decennial 


(Z/^€-  ij%e(U^€^n^^j   Cy'U4-4£^^d^^    t^^n-c^  <Z^t^i^i>iyiyCMf  -a^ 


<)y^ 


^tea/a>&  vt^U^. 


Celebration.  17 


18  Decennial 

The  invitations  to  the  lectures  were  sent  to  such  persons  as  were  con- 
sidered to  be  particularly  interested  in  the  subjects  in  question,  of  whom 
over  one  hundred  accepted.  Many  declinations  were  inevitable  and 
expected,  owing  to  the  unfavorable  season  of  the  year  and,  perhaps  in 
part,  to  the  somewhat  too  short  notice  given.  The  lecturers  all  arrived 
in  due  season,  and  were  entertained  as  follows :  — 

Professor  Emile  Picard,  by  Professor  W.  E.  Story. 

Professor  Ludwig  Boltzmann,  by  Assistant  Professor  A.  G.  Webster. 
Professor  Angelo  Mosso,  by  President  G.  Stanley  Hall. 

Professor  S.  Ramon  y  Cajal,     by  Hon.  Stephen  Salisbury. 
Professor  August  Forel,  by  Dr.  Adolf  Meyer. 

The  lectures  were  held  in  the  large  lecture-room  on  the  first  floor,  and 
were  well  attended.  Professors  Picard  and  Cajal  lectured  in  French,  and 
Professors  Boltzmann,  Mosso,  and  Forel  in  German.  Their  lectures  are 
printed  in  full  elsewhere  in  this  volume. 

Many  social  functions  occurred  during  the  week  ending  July  8.  On 
Wednesday  evening.  Professor  Story  received  informally  the  attendants 
on  the  lectures  of  Professors  Picard  and  Boltzmann  ;  on  Thursday  evening 
President  Hall  gave  a  reception  to  all  the  visitors  ;  and  on  Friday  after- 
noon and  evening  the  whole  company  was  entertained  by  Hon.  Stephen 
Salisbury  at  the  Quinsigamond  Boat  Club  house. 

The  second  part  of  the  celebration  occurred  on  Monday  morning, 
July  10,  beginning  at  10.30,  in  the  University.  The  professors  had 
adopted  academic  costume,  and  many  distinguished  guests  were  seated 
upon  the  platform.  The  exercises  opened  with  prayer  by  the  Rev.  Alex- 
ander H.  Vinton,  Rector  of  All  Saints'  Church. 

A  few  extracts  from  congratulatory  letters  were  read  by  Professor 
Story,  which  are  printed  elsewhere  in  this  volume.  Brief  congratulatory 
addresses  were  made  by  President  Faunce,  of  Brown  University,  repre- 
senting the  New  England  college  presidents ;  and  Professor  Bowditch  of 
the  Harvard  Medical  School,  representing  the  higher  scientific  institutions 
of  the  state. 

President  Faunce  said :  — 

"  I  count  it  a  very  happy  fact  that  the  first  occasion  on  which  I  am  to 
officially  speak,  representing  Brown  University,  is  at  this  anniversary  at 
Clark  University.  I  bring  you  to-day  greetings  from  an  institution  of  the 
higher  learning  founded  in  1764  to  a  university  founded  in  1887.     It  is 


Celebration,  19 

safe  to  say  that  Clark  University  has  done  more  to  widen  the  confines  of 
human  knowledge  than  any  other  American  college  in  one  hundred  and 
fifty  years. 

"  When  Professor  J.  P.  Cooke,  of  Harvard,  applied  to  the  Faculty  for 
chemicals  and  apparatus  for  experiment,  he  was  told  he  must  secure  the 
materials  at  his  own  expense,  and  that  he  must  be  responsible  for  any 
explosions  or  damage  in  consequence  of  his  experiments.  From  that  day 
to  this  is  a  long  step.  Our  method  of  applying  nature  has  been  trans- 
formed within  a  very  few  years.  The  distance  between  Achilles'  coach 
and  the  English  stage-coach  is  not  the  same  as  that  between  the  stage- 
coach and  the  Empire  State  express.  The  difference  between  the  Phceni- 
cian  galleys  and  the  Bon  Homme  Richard  is  not  the  difference  between 
the  Bon  Homme  Richard  and  the  modern  battleship.  The  little  world  of 
Shakespeare  has  become  one  vast  universe  of  learning,  and  the  field  has 
broadened  almost  infinitely  in  all  directions,  and  the  goal  is  the  far-off 
divine  event  toward  which  the  whole  creation  moves. 

"In  this  movement  of  scholarship  the  enrichment  of  one  institution 
is  the  enrichment  of  all,  the  enfeeblement  of  one  is  the  enfeeblement  of 
all.  You  have  received  at  this  celebration,  almost  Spartan-like  in  its  sim- 
plicity, the  congratulations  not  alone  of  America,  but  of  Berlin  and 
Munich  and  Vienna,  because  your  advance  and  success  is  the  advance 
of  all.  Only  geographically  and  superficially  are  the  leaders  of  modern 
scholarship  divided,  and  so  we  congratulate  you,  not  because  you  have 
duplicated  existing  plants,  but  that  you  have  filled  a  place  hitherto 
unfilled  and  have  broken  new  ground. 

"  Here  among  all  the  institutions  of  learning  you  have  not  detracted 
from  the  success  of  other  institutions,  you  have  placed  fresh  laurels  on  the 
heads  of  each.  All  of  us  feel  a  warm  interest  and  admiration  for  this 
University  because  of  the  simple,  quiet,  and  noble  work  done  within  these 
walls." 

Dr.  Bowditch  said  that  he  was  quite  unprepared  to  say  much,  and  he 
thought  it  just  as  well,  for  he  belonged,  in  the  words  of  Dr.  Holmes,  to 
the  "silent  profession."  He  paid  a  tribute  to  the  felicitous  speech  of 
Dr.  Faunce,  which  left  him  little  to  say.  Dr.  Bowditch  spoke  of  the 
great  work  in  scientific  research  being  conducted  by  the  institution,  and, 
after  some  wishes  for  its  prosperity,  congratulated  the  youngest  college 
in  the  name  of  the  oldest  college  in  Massachusetts. 


20  Decennial 

Then  followed  the  address  by  President  Hall,  printed  elsewhere  in  this 
volume. 

The  honorary  degree  of  Doctor  of  Laws,  honoris  causd,  was  then  con- 
ferred, for  the  first  time,  upon  the  five  foreign  professors  in  the  following 
terms :  — 

"  By  virtue  of  the  authority  vested  by  the  Commonwealth  of  Massachu- 
setts in  the  Board  of  Trustees  of  Clark  University,  and  by  them  dele- 
gated to  me,  I  now  create  you  Doctor  of  Laws,  ho7ioris  causd,  and  by  this 
token  [presenting  diploma]  invest  you  with  all  the  dignities  thereunto 
appertaining."     Brief  responses  were  made,  of  which  translations  follow. 

LUDWIG   BOLTZMANN. 

The  problem  of  science  is  a  twofold  one :  first,  to  advance  our  knowledge 
of  nature  independently  of  any  practical  application  ;  and  second,  to  make 
practical  applications  of  the  knowledge  gained.  Although  to  a  superficial 
observer  it  may  seem  that  the  latter  is  of  greater  importance,  the  develop- 
ment of  humanity  has  shown  in  the  most  convincing  way  that  the  first 
kind  of  activity  is  not  only  of  paramount  importance,  but  that  the  leading 
role  belongs  to  it.  In  fact,  it  is  only  thanks  to  the  pioneers  of  science 
who,  laying  aside  all  practical  applications,  penetrate  deeper  and  deeper 
into  the  essence  and  arrangement  of  the  forces  of  nature,  that  humanity 
has  obtained  that  sway  over  the  laws  of  nature  which  makes  possible  the 
present  practical  achievements. 

The  German  universities  have  devoted  themselves  at  all  times  to  the 
nurture  of  pure  science  apart  from  its  practical  applications,  although  but 
one  of  the  four  university  faculties  is  consecrated  to  it,  and  that  one  not 
entirely.  It  must  be  considered  as  a  good  omen,  therefore,  that  here  in 
America,  which  is  usually  taken  to  be  the  land  of  practical  men,  the  ideal 
of  a  place  entirely  consecrated  to  the  service  of  pure  science,  unattainable 
in  Germany,  has  found  its  realization,  so  that  I,  who  am  body  and  soul  a 
German  professor,  deem  it  a  great  honor  to  have  conferred  on  me  in  this 
place,  the  greatest  distinction  which  the  University  can  grant.  While 
desiring  Clark  University  to  flourish  and  thrive  in  the  intimate  conviction 
that  the  whole  scientific  world  is  interested  in  her  prosperity,  I  express 
my  thanks  to  the  President  and  all  its  members  for  the  high  honor 
bestowed  upon  me  to-day. 


Celebration.  21 

Santiago  Ramon  y  Cajal. 

I  OFFER  my  most  cordial  thanks  to  Clark  University  for  the  honorable 
distinction  she  has  bestowed  upon  me  in  spite  of  my  small  deserts  by 
granting  to  me  the  degree  of  doctor  of  laws  by  this  learned  body,  the 
remembrance  of  which  will  never  fade  from  my  memory.  This  honor 
I  deem  to  be  the  prize  of  the  greatest  value  which  my  modest  researches 
have  procured  for  me,  and  the  one  which  will  encourage  me  most  in  my 
worship  of  the  laboratory  tasks  and  of  the  study  of  nature.  This 
honorary  distinction,  as  well  as  the  invitation  which  Clark  University 
condescended  to  make  me  to  take  part  in  the  conferences  for  solemnizing 
the  tenth  anniversary  of  its  foundation,  shows  once  more  that  the  men  of 
science  know  of  no  frontiers,  and  that  they  form  a  universal  family,  whose 
solidarity  and  fellow-feeling  place  them  high  above  the  wrangle  of  mate- 
rial interests  and  selfish  struggles  of  nationalities. 

It  was  truly  a  happy  idea  to  create  in  America  a  university  of  higher 
studies,  devoted  not  only  to  the  labor  of  teaching,  but  also  very  especially 
to  giving  impulse  to  pure  science.  It  has  been  said  many  times,  but  never 
enough,  that  there  is  no  lasting  industrial  progress  if  it  is  not  connected, 
as  a  brook  with  it^  source,  with  the  creation  of  original  science. 

No  matter  how  great  the  practical  genius  of  a  nation,  it  is  impossible 
for  it  to  preserve  its  political,  commercial,  and  industrial  hegemony,  unless 
it  comes  out  intellectually  superior  to  other  nations,  unless  it  attends  with 
equal  care  to  the  laboratory  and  to  the  mill,  to  the  ideas  as  well  as  to  the 
inventions,  to  the  philosophy  and  to  the  science  which  guide  as  well  as  to 
the  art  which  carries  out. 

This  happy  alliance  between  theory  and  practice  is  what  places  Ger- 
many to-day  at  the  head  of  civilization.  It  would  be  easy  to  adduce  num- 
berless examples  of  the  supremacy  which  industry,  founded  on  science, 
holds  over  empirical  industry  created  at  haphazard  according  to  the 
inventive  character  of  each  nation.  I  will  quote  only  two  —  the  chemical 
industry  of  the  aniline  dyes  created  chiefly  in  Germany,  which  assures 
to  that  nation  an  immense  wealth ;  and  the  optical  industry  representing 
all  kinds  of  apparatus  (microscopes,  photographical  and  astronomical 
object-glasses)  which  sprung  up  under  the  inspiration  of  the  great 
mathematicians,  Abbe,  Rudolph,  Goertz,  and  others,  and  which  by  its 
manifest  superiority  over  that  of  other  nations  procures  to  Prussia  a 
monopoly  which  makes  the  whole  world  her  tributary. 


22  Decennial 

That  is  the  right  way,  the  only  one  which  leads  to  glory,  wealth, 
and  power.  I  trust  that  the  creation  of  Clark  University  may  give  the 
signal  for  foundino^  in  America  other  similar  institutions  embracing  a  still 
larger  number  of  branches  of  science,  and  having  as  their  primary  object 
the  wresting  of  secrets  from  nature,  supplying  industry  and  arts  with 
principles  and  facts  capable  of  fruitful  applications,  forming  the  research 
spirit  of  the  new  generation,  freeing  it  from  the  clogs  of  routine  and 
imitation,  and  finally  forming  the  foundation  of  a  splendid  civilization 
superior  in  groundwork,  as  well  as  in  form,  to  that  of  the  European 
nations. 

Atjgtjst  Foeel. 

I  THANK  you  heartily  for  the  great  honor  you  have  bestowed  upon  me 
by  conferring  upon  me  the  degree  of  doctor  of  laws,  honoris  causd,  of 
Clark  University.  But  I  accept  this  honor  less  in  my  own  person  than 
as  a  representative  of  Switzerland  at  your  celebration  —  in  the  name  of 
my  little  fatherland.  Although  nowadays  the  Swiss  Federation  disap- 
pears beside  the  powerful  republic  of  the  United  States,  yet  she  prides 
herself  still  on  being  the  little  old  mother  of  democracy,  which  has  fought 
for  her  free  rights  for  centuries,  and  has  maintained  them  up  to  the 
present  day.  I  offer  my  heartiest  congratulations  for  the  brilliant  success 
which  Clark  University  has  achieved  during  the  short  time  of  its  exis- 
tence in  the  high  domains  of  philosophy,  pedagogy,  and  of  many  a  scientific 
foundation  of  social  questions.  But  we  must  also  offer  our  heartiest 
thanks  and  congratulations  for  the  generous  and  magnificent  gifts  of 
American  citizens  for  the  furtherance  of  scientific  and  social  progress. 
Allow  me  to  add  a  wish.  Let  Clark  University  continue  to  pursue  — 
under  the  successful  guidance  of  her  excellent  President,  Professor  G. 
Stanley  Hall  —  her  researches  in  the  regions  of  psychology  and  pedagogy 
together  with  those  on  the  brain  and  its  life,  and  thus  to  further  the 
investigation  and  the  building  up  of  truth  in  the  teeth  of  all  prejudices. 
Let  her  help  to  bury  the  old  roads  of  barren  metaphysical  dogmas  and 
speculations,  and  thus  develop  in  its  entirety  the  only  fruitful  ethically 
built-up  progressive  method  of  scientific  investigation  in  these  domains, 
as  a  blessing  to  our  posterity  and  for  the  good  of  a  better  and  happier 
humanity. 


Celebration.  23 

Angelo  Mosso. 

I  OFFER  my  thanks  to  Clark  University  for  the  honor  bestowed  upon 
me.  I  shall  carry  with  me  to  Italy  a  happy  remembrance  of  the  many 
proofs  of  sympathy  and  friendship  which  I  have  received  in  the  Uni- 
versity and  the  city  of  Worcester.  It  is  not  only  the  expression  of  my 
gratitude  that  I  offer  you,  but  also  my  great  admiration  for  all  that  I 
saw  in  your  University,  and  especially  the  development  in  experimental 
psychology  under  the  happy  impulse  which  the  President  has  given  to 
this  branch  of  science.  It  is  not  only  on  my  own  account  that  I  offer 
you  my  thanks,  it  is  also  because,  on  my  return  to  Italy,  I  hope  to  found 
in  the  University  of  Turin  a  school  of  experimental  psychology. 

Emile  Picard. 

I  offer  my  heartiest  thanks  to  the  President  and  Professors  of  Clark 
University  for  the  degree  just  conferred  upon  me.  I  have  been  also  greatly 
touched  by  the  honor  you  bestowed  upon  me  by  inviting  me  to  give  a  few 
lectures  during  this  academic  celebration.  Your  desire  was  thus  to  bear 
witness  to  your  sympathy  with  men  of  science  in  France.  We  follow  on 
our  side,  in  France,  with  great  interest  the  American  scientific  movement, 
and  we  rejoice  in  seeing  closer  relations  established  between  our  universi- 
ties and  those  of  this  country.  Science  treads  its  ascending  march  on 
different  roads,  and  research  work  requires  to-day  the  most  varied  apti- 
tudes. The  initiative  and  the  energy  which  are  prevalent  in  this  country 
will  not  be  wanting  in  occasions  for  displaying  themselves,  and,  in  all 
branches  of  studies,  the  American  scientists  will  be  able  to  erect  some- 
thing equivalent  to  those  large  telescopes  by  means  of  which  your  astrono- 
mers have  made  such  beautiful  discoveries.  It  is  in  the  universities  which, 
like  this  one,  are  devoted  to  research,  that  the  scientific  movement  is  bound 
to  have  its  origin.  From  everything  I  have  seen  and  heard  for  the  last 
few  days,  I  am  certain  that  the  eminent  professors  of  this  University 
devote  themselves  with  success  to  this  noble  task,  and  I  beg  to  offer  my 
most  sincere  wishes  for  the  continuance  of  the  brilliant  development  of 
Clark  University. 

The  exercises  concluded  with  prayer  by  Dr.  Vinton. 

The  closing  exercise  of  the  decennial  was  a  reception  which  was 
attended  by  between  five  hundred  and  six  hundred  ladies  and  gentlemen 


24  Decennial  Celebration, 

of  Worcester.  The  arrangements  had  been  made  under  the  direction  of 
Assistant  Professor  Henry  Taber  and  Professor  William  E.  Story.  The 
large  lecture-room  and  corridors  were  decorated  with  festoons  of  green 
and  white,  the  flags  of  the  United  States  and  of  the  native  countries  of 
the  foreign  guests,  and  with  potted  plants.  A  collation  was  served  in  the 
library,  and  many  pieces  of  apparatus  were  exhibited  in  operation  in  the 
physical  and  psychological  laboratories. 

The  following  persons  received  :  President  G.  Stanley  Hall,  Miss 
Florence  E.  Smith  of  Newton  Centre,  Mass.,  Mrs.  A.  W.  Beals  of  Stam- 
ford, Conn.,  Hon.  Stephen  Salisbury,  Dr.  Edward  Cowles,  Miss  Gage, 
Professor  and  Mrs.  William  E.  Story,  Assistant  Professor  and  Mrs.  Arthur 
G.  Webster,  Assistant  Professor  and  Mrs.  Clifton  F.  Hodge,  Assistant 
Professor  Edmund  C.  Sanford,  Miss  Sanford,  Assistant  Professor  Henry 
Taber,  Dr.  and  Mrs.  A.  F.  Chamberlain,  the  foreign  lecturers,  Senora 
Ramon  y  Cajal,  and  Frau  Boltzmann. 

The  press  of  Worcester  gave  very  full  and  detailed  accounts  of  all 
that  transpired  during  the  week  except  the  scientific  lectures,  all  of  which 
were  in  foreign  languages  and  upon  very  technical  subjects. 

The  following  original  documents  have  been  bound  and  filed  in  the 
University  library :  — 

(1)  The  congratulatory  letters,  telegrams,  etc. 

(2)  The  correspondence  with  the  foreign  lecturers,  and  the  letters  of 
acceptance  and  declination  from  American  professors. 

(3)  The  letters  of  acceptance  and  declination  to  the  reception  in  the 
evening. 

The  weather  was  somewhat  warm  during  the  first  few  days,  but  was 
clear  and  cool  on  Saturday,  Sunday,  and  Monday.  The  hospitality  of 
Worcester  people  was  all  that  could  be  desired. 


CONGRATULATIONS. 


The  following  extracts  are  taken  from  many  hundred  congratulatory- 
letters,  personal,  official,  and  from  institutions  and  educators  of  all  grades 
and  many  lands. 

Congratulations  on  the  conclusion  of  the  University's  first  decade,  and  best 
wishes  for  the  successful  continuance  of  the  work  it  has  undertaken. 

William  McKinlbt,  Washington,  D.C., 
President  of  the  United  States. 

The  attraction  will  be  strong  to  all  who  are  interested  in  the  great  subjects 
which  these  distinguished  men  will  discuss,  or  in  intellectual  eminence  for  its 
own  sake.  Your  occasion  will  be  the  most  distinguished  gathering  that  will 
occur  in  all  New  England  this  summer.  .  .  . 

The  high  plane  of  the  work  done  at  Clark  University,  the  only  institution 
in  our  country  exclusively  devoted  to  original  research  and  the  instruction  of 
advanced  investigators,  so  far  as  I  am  aware,  is  well  known  to  all  who  have 
followed  the  course  of  the  University.  Modestly,  and  without  ostentation,  it 
has  pursued  its  noble  ideals.  If,  under  your  able  direction,  its  means  were  more 
extensive,  the  University  would,  doubtless,  become  the  centre  of  a  still  larger 
circle  of  influence  in  the  training  of  men  for  the  prosecution  of  original  research 
and  the  conduct  of  similar  work  in  other  institutions.  I  trust  that  your  own 
large  plans  and  those  of  the  founder  of  the  University  may  enjoy  a  complete 
realization,  and  that  its  future  may  be  crowned  with  the  high  success  which  so 
great  an  enterprise  rightly  deserves. 

Felicitating  the  honored  founder,  yourself,  the  trustees,  and  your  colleagues 
in  the  faculty  upon  the  great  occasion  you  are  soon  to  celebrate, 

David  J.  Hill,  Washington,  D.C., 
Assistant  Secretary  of  State. 

It  is  one  of  the  chief  regrets  of  my  life  that  I  cannot  attend  the  celebration 
of  Clark  University,  Be  assured  that  no  reason  personal  to  myself  has  pre- 
vented my  attendance.  I  have  seriously  considered  the  question  of  crossing  the 
Atlantic  for  the  purpose,  and  coming  back  here  immediately  afterward.  But 
that  seems  impracticable. 

25 


26  Extracts  from 

We  have  to  congratulate  the  University  upon  ten  years  of  success.  It  was 
not  to  be  expected  that  an  institution  whose  aim  is  to  lift  the  university  educa- 
tion, not  only  of  this  country,  but  of  the  world,  to  a  higher  plane,  and  to  break 
out  a  new  and  untrodden  path,  should  command  popularity  in  the  beginning,  or 
that  its  success  should  at  once  be  recognized  by  the  general  public.  But  we 
have  no  cause  for  regret  or  for  discouragement.  Teachers  whom  we  have  edu- 
cated are  found  in  institutions  of  the  first  class  in  all  parts  of  the  country,  and 
all  parts  of  the  world  have  sent  representatives  to  receive  our  instruction.  This 
is  largely  due  to  the  wise  and  far-sighted  intelligence  of  the  founder,  and,  next, 
to  your  own  constant  and  self-sacrificing  labors. 

There  have  been  times  during  these  ten  years  when  we  have  been  tempted 
to  think  that  the  people  of  Worcester  have  been  cold,  and  have  been  lacking  in 
the  liberality  which  we  had  hoped  from  them  when  we  started.  But  in  looking 
at  the  history  of  other  institutions  which  are  now  useful  and  flourishing,  it  will 
be  seen  that  they  had  in  the  beginning  a  like  experience.  I  remember  well  a 
time  when  it  almost  seemed  impossible  to  get  the  people  of  Worcester  to  endow 
a  public  library.  But  the  hour  came  and  the  man  came,  and  our  public  library 
is  now  munificently  endowed  and  is  a  model  of  library  administration.  The 
Polytechnic  Institute  had  its  day  of  small  things.  But  the  liberality  of  two 
citizens  of  Worcester  of  the  same  name  and  race,  whose  two  lives  seem  almost 
like  the  prolonged  life  of  one  individual,  came  to  its  aid,  and  it  is  now  doing  its 
work  with  large  endowments,  and  its  scheme  has  been  copied  by  other  institu- 
tions all  over  the  country.  I  do  not  for  a  moment  doubt  that  the  time  will  come 
when  our  endowments  will  enable  us  to  maintain  in  the  entire  circle  of  univer- 
sity education  the  position  which  we  have  taken  and  hold  with  regard  to  a  few 
subjects.  Already  an  eloquent  orator,  formerly  head  of  the  National  Catholic 
University  at  Washington,  has  referred  to  Clark  as  "  that  little  institution  in 
Worcester  which  has  added  a  new  story  to  university  education,  and 

'  Wliich  allures  to  brighter  worlds  and  leads  the  way.'  " 

An  eminent  professor  of  science  from  the  English  Cambridge  declared  at  a 
meeting  in  the  British  Association,  in  the  presence  of  famous  scholars  from  all 
parts  of  the  world,  that  there  is  one  thing  that  England  envies  America,  and 
that  is  Clark  University. 

There  is  nothing  except  the  country  itself  which  ought  to  inspire  a  deeper 
devotion  in  its  children  than  a  university.  As  time  goes  on  this  feeling,  made 
up  of  love  and  gratitude,  will  be  found  in  fullest  measure  among  the  alumni  of 
Clark.  As  they  go  out  to  reap  the  harvests  of  success  in  life,  they  will  repay 
to  their  alma  mater,  in  their  own  way,  the  great  debt  they  owe  her.  When  that 
time  comes  I  have  no  fear  that  her  endowments  will  not  be  ample  to  accomplish 
the  work  she  has  undertaken.  In  the  meantime  those  of  us  to  whom  the  con- 
fidence of  the  founder  has  committed  a  share  in  her  administration  must  renew 
our  own  vows  of  fidelity  to  her  service. 

Among  the  many  public  honors  which  the  undeserved  kindness  of  my  fellow- 


Congratulatory  Letters.  27 

citizens  has  bestowed  upon  me,  I  count  none  higher  than  my  selection  as  one  of 
the  first  board  of  trustees  of  this  institution.  I  trust  that  your  celebration  will 
be  full  of  delight  for  those  who  gather  there,  that  they  will  look  forward  with 
bright  hopes  to  the  future,  and  that  an  immortality  of  fame  and  usefulness  may 
await  the  institution  which  now  celebrates  its  tenth  birthday. 

George  F.  Hoar, 

United  States  Senator. 

I  learn  from  your  formal  letters  of  invitation  that  you  are  to  celebrate  the 
close  of  the  first  decade  of  Clark  University.  It  is  one  of  the  most  wonderful 
careers  to  be  chronicled  in  the  history  of  American  education.  I  congratulate 
you  on  your  eminent  success  in  conducting  your  University  in  so  efficient  a 
manner  toward  the  improvement  and  elevation  of  pedagogy  in  the  United 
States.  Your  movement  is  all  the  more  valviable  because  it  challenges  the  aims 
and  purposes  of  the  present  existing  education.  It  is  an  elementary  force  in 
making  the  American  teachers  circumspect  and  reflective,  and  causing  them  to 
seek  deeper  principles  on  which  to  ground  their  practice  and  on  which  to  im- 
prove it.  Hoping  that  there  will  be  a  long  series  of  equally  useful  decades  in 
the  history  of  Clark  University  and  in  your  own  successful  directorship  of  that 

institution, 

W.  T.  Harris,  Washington,  D.C., 

Commissioner  of  Education. 

I  cannot  refrain  from  offering  my  congratulations  to  the  President,  Trustees, 

and  Faculty  for  securing  the  services  of  such  distinguished  lecturers,  as  well  as 

for  the  marked  success  that  has  attended  Clark  University  during  the  first 

decade  of  its  existence. 

Willis  L.  Moore,  Washington,  D.C., 

Chief  of  Weather  Bureau. 

I  must  add  my  profound  appreciation  of  the  great  work  for  the  highest 
science  that  is  being  accomplished  by  you.  The  solid  knowledge  that  consti- 
tutes " Science"  is  a  rather  slow  growth  —  it  can  only  advance  in  proportion  as 
man  frees  himself  from  ancient  errors  and  evolves  higher  powers  of  observation 
and  reason.  The  fine  work  done  at  Clark,  the  excellent  memoirs  published  by 
its  professors,  and  now  these  attractive  lectures,  give  us  all  the  assurance  that 
your  labors  for  the  highest  attainments  in  the  study  and  teaching  of  science 

will  be  abundantly  rewarded. 

Cleveland  Abbe,  Washington,  D.C., 

Weather  Bureau. 

Congratulating  you  on  the  successful  rounding  out  of  the  first  decade  of  the 

University,  and  with  best  wishes  for  the  success   of   the  institution  in  the 

future,  ^   ,  .  -n.  ^ 

W.  J.  McGee,  Washington,  D.C., 

Smithsonian  Institution. 


28  Extracts  from 

I  send  you  most  cordial  greetings  on  the  interesting  occasion,  and  hope  the 
future  of  Clark  will  be  as  successful  as  the  past,  and  that  your  plans  for  scien- 
tific research  may  be  realized  in  the  fullest  degree. 

Carroll  D.  Wright,  Washington,  D.C., 
Commissioner  of  Labor. 

One  may  well  be  envious  of  the  gratification  that  the  generous  founder  of 
Clark  University  must  feel  at  the  world-wide  recognition  of  its  achievements 
during  the  very  first  decade  of  its  existence. 

To  have  established  a  just  claim  upon  the  regard  of  foremost  men  associ- 
ated with  educational  establishments  in  this  country  and  in  Europe  is  of  great 
significance. 

The  work  that  the  University  has  done  and  is  doing  will  continue  to  attract 
to  its  halls  those  rare  geniuses  who,  impressed  with  the  transcendent  importance 
of  the  science  of  Pedagogy,  of  Physiology  and  Psychology,  seek  with  unfailing 
diligence  to  penetrate  their  inmost  depth.  This  work  can  scarcely  fail  to  exer- 
cise a  beneficial  influence  upon  the  schools  of  the  country,  and  become  a  distin- 
guished attraction  to  the  city  which  is  fortunately  the  home  of  the  University, 
whose  citizens  will  give  it  welcome  and  encouragement  and  markedly  recognize 
the  munificence  of  its  founder,  as  well  as  the  labors  of  those  who  have  in  so 
brief  a  time  established  it  among  the  foremost  seats  of  learning. 

Andrew  H.  Green, 

214  Broadway.,  Neio  York  City. 

As  I  shall  not  be  able  to  be  present  during  the  exercises  on  Monday,  July  10, 
celebrating  the  completion  of  the  tenth  academic  year  of  Clark  University,  I 
desire  to  express  in  writing  my  feelings  of  sympathy  and  my  strong  desire  for 
the  success  of  the  University,  and  also  to  extend  to  you  and  your  co-workers  my 
sincere  congratulations  on  this  auspicious  occasion. 

It  is  probably  true  that  the  initiative  step  of  the  institution  was  not  fully 
understood  or  appreciated  by  the  public,  but  during  the  past  ten  years  it  has, 
under  your  able  and  judicious  direction,  steadily  pursued  a  course  well  calcu- 
lated to  win  its  way  to  public  confidence  and  to  an  abiding  position  among 
the  most  eminent  and  distinguished  institutions  of  learning  in  the  civilized 
world. 

The  entire  exercises  attending  the  celebration  are  calculated  to  draw  aside 
the  mystic  veil,  and  when  the  occasion  shall  have  been  numbered  among  past 
events,  the  general  public  will  be  led  to  see  and  know  Clark  University  in  the 
future  as  it  has  been  seen  and  known  in  the  past  by  distinguished  foreign  scien- 
tists and  educators. 

Yes,  rest  assured,  President  Hall,  that  before  the  last  hour  of  the  present 
century  has  been  struck  by  the  unerring  and  mighty  hand  of  time,  Clark  Uni- 
versity, the  far-seeing,  noble,  and  generous  founder,  together  with  the  Univer- 
sity's learned  and  distinguished   first  president,  will   have   been  crowned  by 


Congratulatory  Letters.     ,  29 

truth  and  justice  with  the  laurel  wreath  of  victory,  exalted  merit,  and  uni- 
versal appreciation. 

Thomas  H.  Dodge,  Esq., 
Worcestei'. 

James  Brice  begs  to  be  permitted  to  offer  his  congratulations  upon  that 
occasion. 

Will  you  please  convey  to  them  my  best  wishes  for  the  continued  prosperity 
of  Clark  University.  It  has  a  high  mission ;  for  gathering  in  new  knowledge 
is  a  much  nobler  task  than  distributing  that  which  is  known,  useful  as  the  latter 
may  be. 

I  feel  confident  that  when  your  present  age  is  lengthened  tenfold  and 
your  successors  celebrate  the  centenary,  they  will  hold  up  a  great  record  of 
influence  for  good  in  the  States  and  in  the  world. 

Pkofessor  Michael  Foster, 

University  of  Cambridge,  England. 

Though  thus  tardily,  it  is  none  the  less  heartily,  that  I  congratulate  you  and 
your  colleagues  and  fellow-citizens  in  this  celebration  —  and  this  not  simply  on 
reaching  your  first  natural  period  of  retrospect,  but  on  the  worthy  manner  of  the 
celebration  also.  You  are  certainly  setting  forth  a  feast  of  rare  and  varied 
intellectual  fare,  and  thereby  also  giving  a  great  lesson  to  us  in  the  Old  World 
of  that  return  to  the  international  unity  of  universities,  which  it  is  fitting  that 
you  in  America  should  lead.  Agarn  accept  these  my  best  wishes  for  the  cele- 
bration, with  hearty  congratulations  upon  your  vigorous  and  productive  youth 
—  with  confident  hope  also  of  your  yet  more  productive  maturity. 

Professor  T.  W.  Geddes, 

University  of  Edinburgh,  Scotland. 

Arthur  Bienatme  (Toulon,  France)  addresses  to  the  President  his  most 
sincere  prayers  for  the  prosperity  of  the  University. 

I  address  my  wishes  for  the  brilliant  future  of  your  University. 

Professor  Alfred  Binet, 

Paris,  France. 

I  find  it  unfortunately  impossible  to  avail  myself  of  your  invitation,  for  I 
certainly  would  have  desired  to  enter  into  personal  relations  with  men  who  join 
to  their  high  science  a  largeness  of  view  seldom  to  be  met  with. 

Professor  Jules  Tannery, 
Paris,  France. 


30  Extracts  from 

My  congratulations  on  the  completion  of  the  tenth  academic  year  of  the  Uni- 
versity, with  my  best  wishes  for  its  increase  and  prosperity. 

Pkofessor  Adolf  Baginskt, 

University  of  Berlin,  Germany. 

I  avail  myself  of  this  occasion  to  express  my  heartiest  wishes  for  the  further 
prosperity  of  your  University.  I  rejoice  at  the  admirable  way  in  which  you  are 
to  celebrate  the  foundation  of  your  institution,  thereby  showing  that  it  is  to 
remain  what  it  has  hitherto  been:   the  home  of  scientific  investigation  and 

culture. 

Pkofessor  Max  Dessoir, 

Berlin,  Germany. 

I  express  my  heartiest  wishes  for  the  prosperity  of  your  University,  whose 
scientific  activity  has  so  soon  won  for  it  a  high  place  among  the  universities  of 

your  country. 

Professor  Benno  Erdmann, 

Bonn,  Germany. 

In  your  effort  to  unite  the  nations  under  the  banner  of  unselfish  science, 
accept  my  most  cordial  congratulations  and  wishes  for  prosperity. 

Professor  Paul  Flechsig, 

University  of  Leipzig,  Germany. 

I  request  you  to  receive  my  sincerest  congratulations  to  this  academical 
solemnity,  and  the  expression  of  my  hope,  that  your  institution,  highly  ad- 
vanced through  many  difiiculties  and  sacrifices,  may  enjoy  the  most  splendid 

prosperity  for  many  secula. 

Professor  Ernst  Haeckel, 

University  of  Jena,  Germany. 

I  send  to  you  and  Clark  University  best  wishes  for  success. 

Professor  Felix  Klein, 

University  of  Gottingen,  Germany. 

Permit  me  to  express  my  warmest  wishes  for  the  future  prosperity  of  your 

University,  which,  called  to  life  ten  years  ago,  has  already  won  such  deserved 

success. 

Professor  Kuhne, 

University  of  Heidelberg,  Germany. 

Accept  my  heartiest  congratulations  on  your  approaching  celebration,  and 
may  it  be  the  dawn  of  a  still  more  momentous  era  than  the  preceding  one  has 
already  been. 

Professor  Oswald  Kulpe, 

University  of  Wurzburg,  Germany. 


Congratulatory  Letters.  31 

May  the  following  decennium  of  Clark  University  be  prosperous  in  its 
development  and  rich  in  scientific  results. 

Professor  Lindemann, 

University  of  Munchen,  Germany. 

I  express  my  good  wishes  on  the  occasion  of  the  celebration. 

Professor  Max  Noether, 

University  of  Erlangen,  Germany. 

I  do  not  want  to  let  slip  the  opportunity  of  expressing  my  best  wishes  for 
the  University  which  has  done  so  much  for  science,  and  is  spoken  of,  particu- 
larly in  Germany,  with  the  highest  respect  and  esteem. 

Professor  Ranke, 

University  of  Munchen,  Germany. 

With  the  best  wishes  for  the  growth  and  success  of  your  University, 

Professor  W.  Rein, 

University  of  Jena,  Germany. 

I  offer  my  best  wishes  for  the  welfare  and  progress  of  the  University, 

Professor  C.  Rdnge, 

Hannover,  Germany. 

Permit  me  to  send  my  heartiest  congratulations  on  this  celebration.  Under 
your  guidance  Clark  University  has,  in  the  ten  years  of  its  existence,  already 
won  for  itself  a  high  reputation  in  the  whole  scientific  world.  May  the  second 
decennium  continue  like  the  first  to  advance  and  increase  science,  and  may  it 
be  granted  to  you,  Mr.  President,  for  many  years  to  come  to  be  the  standard- 
bearer  of  the  scientific  labors  of  Clark  University. 

Professor  Hermann  Schiller, 

University  of  Giessen,  Germany. 

Wishing  the  University  further  prosperity  and  progress. 

Professor  P.  Schur, 

Karlsruhe,  Germany. 

I  remember  my  sojourn  in  America  and  the  kind  reception  which  I  met 
with  in  Worcester.  I  should  rejoice  to  have  the  opportunity  to  renew  the 
hospitality  shown  me  by  yourself  and  by  your  colleagues. 

Professor  E.  Study, 

University  of  Greifswald,  Germany. 

May  the  young  University,  which  has  already  developed  so  auspiciously, 
continue  according  to  the  old  saying :   Vivat,  floreat,  crescat ! 

Professor  Waldeter, 
«•  University  of  Berlin,  Germany. 


32  Extracts  from 

I  should  have  also  been  especially  desirous  of  bringing  to  you  my  own 
recognition  of  what  has  hitherto  been  accomplished  and  my  cordial  wishes  for 
the  future.  I  follow  with  great  interest  particularly  the  psychological  works 
which  proceed  from  your  University  and  are  published  in  the  American  Journal 
of  Psychology.  I  have  always  received  from  them  the  impression  that  the 
psychological  and  pedagogical  departments  of  your  University  belonged  to  the 
most  important  institutions  of  their  kind. 

May  Clark  University  complete  the  second  decennium  of  its  existence 
with  like,  and  where  possible,  increasing  glory ! 

Professor  W.  Wdndt, 

University  of  Leipzig,  Germany. 

Accept  my  warmest  wishes  for  the  development  of  the  University. 

Professor  Ed.  Wetr, 

University  of  Prague,  Austria. 

I  feel  a  great  pleasure  in  congratulating  your  Clark  University  on  the  cele- 
bration of  the  festival ;  and  allow  me  to  express  the  hope  that  your  University 
may    extend  its  activity  with  every  year  to  the  honor  of  its  President,  its 

Trustees,  and  all  its  Members. 

Professor  S.  E.  Henschen, 

University  of  Upsala,  Sweden. 

I  beg  you  to  receive  my  cordial  congratulations  on  the  occasion  of  the 

beautiful  decennium  which  your  University  has  completed.     I  hope  that  this 

seat  of  learning  shall  have  a  future  correspondingly  to  the  excellent  manner  in 

which  it  has  begun  its  life. 

Professor  H.  Hoffding, 

University  of  Copenhagen,  Denmark. 

I  beg  to  present  my  sincere  congratulations  upon  the  erection  of  a  scientific 
centre,  the  decennium  of  which  you  are  to  celebrate  in  so  fitting  a  manner. 

Professor  Zeuthen, 

University  of  Copenhagen,  Denmark. 

I  send  you  the  best  wishes  for  the  success  of  your  celebrated  University, 

Professor  Vito  Volterra, 

University  of  Turin,  Italy. 

Eternal  prosperity  to  the  vigorous  propagator  of  light. 

Professor  Stephanos, 

University  of  Athens,  Greece. 

Dr.  Wesley  Mills  (McG-ill  University,  Montreal,  Canada)  wishes  the  Uni- 
versity every  success  in  the  future.      • 


Congratulatory  Letters.  33 

Witli  best  wishes  for  the  continued  prosperity  of  Clark  University, 

Professor  J.  Squair, 

University  of  Toronto^  Canada. 

President  Angell  (University  of  Michigan)  congratulates  them  on  the 
useful  work  which  the  University  has  already  accomplished. 

With  hearty  congratulations  for  what  you  have  already  achieved  as  President 
of  Clark  University,  and  in  full  assurance  of  a  great  future  before  you, 

Henry  Barnard,  Hartford,  Conn., 

Ex-U.  S.  Commissioner  of  Education. 

William  W.  Birdsall  (President  Swarthmore  College)  desires  to  extend 
congratulations  upon  the  completion  of  the  tenth  year  of  Clark  University. 

I  congratulate  you  most  heartily  on  the  splendid  work  which  Clark  Uni- 
versity has  accomplished  during  the  ten  years  of  its  existence.  Nothing  in 
our  educational  work  has  reflected  greater  honor  upon  the  American  system 
than  the  high  ideals  so  successfully  maintained  at  Clark  University. 

President  John  E.  Bradley, 

Illinois  College. 

Good  wishes  to  the  University  in  all  its  undertakings,  and  congratulations  to 
President,  Trustees,  and  Faculty  upon  the  completion  of  ten  years  of  distin- 
guished usefulness.  Professor  C.  L.  Bristol, 

New  York  University. 

My  deepest  wish  is  that  Clark  may  do  as  much  more  for  the  advancement  of 
science  and  the  deepening  of  the  true  university  spirit  in  the  next  decennium 

as  it  has  in  the  one  now  closing. 

Professor  Edward  F.  Buckner, 

Teachers''  College,  New  York  City. 

I  beg  leave  to  extend  to  you  my  most  sincere  congratulations  on  the  work 
that  Clark  University  has  accomplished  under  your  guidance,  since  the  time  of 
its  founding,  ten  years  ago. 

As  a  Fellow  of  the  University,  I  enjoyed  opportunities  for  work  that  other 
institutions  could  not  afford,  and  I  found  your  efforts  to  provide  books,  instru- 
ments, and  material  as  effectual  as  they  were  untiring. 

As  a  Graduate  I  have  found  inspiration  in  your  zeal  for  the  furtherance  of 
all  that  can  advance  education  and  science. 

I  have  followed  the  development  of  the  University  with  pride.  The  first 
high  ideals  have  not  been  lowered,  and  Clark  remains,  as  it  was  at  its  founda- 
tion, a  University  for  Universities. 

Professor  H.  C.  Bumpus, 
Brown  University. 


34  Extracts  from 

No  undertaking  nor  movement  has  made  so  clear  and  definite  impress  upon 
the  educational  thought  of  America  nor  established  guiding  lines  of  control 
so  distinctly  in  pedagogical  and  psychological  progress  as  the  suggestions  and 
tendencies  which  have  emanated  from  Clark  University.  Though  the  institu- 
tion is  yet  in  its  infancy,  though  the  students  in  point  of  numbers  have  been 
limited,  yet  its  influence  has  penetrated  every  state  in  the  Union,  has  entered 
practically  every  educational  institution  of  the  land,  from  university  to  kinder- 
garten, and  has  quickened  the  spirit  of  educational  conferences,  from  those  of 
national  repute  to  those  of  the  little  teachers'  meetings  of  the  village  school. 

Granting  the  truth  of  the  educational  view  for  which  Clark  University 
stands,  and  allowing  for  the  singularly  forceful  methods  of  instruction  by  the 
President  and  Faculty  within  the  institution,  and  the  energy  with  which  its 
mission  has  been  prosecuted,  it  is  nevertheless  still  a  marvel  that  its  influence 
should  have  become,  in  this  brief  space,  so  widespread  and  vigorous.  The  facts 
which  stand  prove  the  wisdom  of  the  plan  of  an  institution  which  should  be 
exclusively  graduate,  selecting  as  its  students  a  limited  number  of  mature 
thinkers  who  should  be  inspired  by  the  power  wliich  ever  comes  from  the  con- 
tact with  original  investigation  and  a  faculty  of  original  investigators. 

rREDERicK  BuRK,  President  State  Normal  School,  San  Francisco,  and 

President  Clark  University  Alumni  Association  of  California. 

I  send  my  best  wishes  for  the  success  of  the  anniversary  exercises  and  for 
the  continued  and  enlarged  prosperity  of  the  University. 

President  Nathaniel  Butler, 

Colby  University. 

Kindly  accept  my  congratulations  upon  the  completion  of  your  tenth  aca- 
demic year. 

Professor  E.  H.  Chittenden, 

Director  Sheffield  Scientific  School. 

I  desire  to  congratulate  the  Faculty  of  the  University  on  the  great  work 
accomplished  within  a  comparatively  short  period. 

Brother  Chrtsostom, 

Manhattan  College. 

We  rejoice  with  your  many  friends  in  the  successful  rounding  out  of  Clark 
University's  first  decade.  It  is  a  consolation  to  the  generous  benefactor  that 
the  world  recognizes  the  merit  of  the  Institution,  which  his  munificence  estab- 
lished and  maintains.  Coming  into  existence  the  same  year,  holding  similar 
views  as  to  the  place  of  graduate  work,  having  the  highest  ideals  of  university 
endeavor,  striving  earnestly  to  realize  them  in  spite  of  all  difiiculty,  our  two 
Universities  have  always  felt  strong  attachments  for  one  another,  and  a  more 
than  ordinary  interest  in  one  another's  success.     The  Catholic  University  ten- 


Congratulatory  Letters,  35 

ders  you  its  most  cordial  greeting  on  this  the  day  of  your  rejoicing.  It  bids  me 
extend  to  you  and  through  you  to  the  University  its  most  sincere  wishes  for 
still  higher  and  greater  success  in  its  chosen  fields. 

Thos.  J.  CoNATT,  Washington,  D.  C, 
Rector  Catholic  University. 

With  many  congratulations  on  the  past  ten  years'  work  of  the  University, 

Professor  Charles  K.  Cross, 

Massachusetts  Institute  of  Technology. 

Professor  C.  B.  Davenport  (Harvard  University)  desires  to  express  his 
appreciation  of  the  brilliant  example  of  research  as  a  primary  university  func- 
tion which  Clark  University  has  for  a  decade  set. 

The  University  and  all  connected  with  it  are  to  be  congratulated. 

Professor  Ellbrt  W.  Davis, 

University  of  Nebraska. 

I  desire  to  express  my  appreciation  of  the  splendid  work  done  by  Clark 

University  during  these  ten  years. 

Professor  Nathaniel  P.  Davis, 
Brown  University. 

I  must  content  myself  with  rejoicing  over  the  unique  intellectual  enterprise 
you  are  carrying  out.  I  may  not  be  informed  regarding  such  matters,  but  it 
seems  to  me  you  have  accomplished  a  sort  of  scientific  coup  cVetat  in  getting 
such  a  group  of  scholars  to  come  to  America  upon  the  occasion  of  your  anniver- 
sary. As  a  disciple  of  Clark  University,  and  an  admirer  of  everything  it  stands 
for,  I  take  pride  in  the  impression  that  must  necessarily  be  made  upon  Ameri- 
can scholarship  by  the  visit  of  such  men.  I  congratulate  all  of  you,  and  hope 
that  everything  you  desire  in  connection  with  the  series  of  lectures  may  be 

realized. 

Professor  George  E.  Dawson, 

Bible  Normal  College,  Springfield,  Mass. 

President  Drown  of  Lehigh  University  begs  for  his  colleagues  and  for 
himself,  to  offer  his  hearty  congratulations  to  the  President,  Trustees,  and 
Faculty  of  Clark  University  on  the  completion  of  a  decade  of  usefulness  in 
the  higher  education,  marked  by  distinguished  services  in  many  lines  of 
original  research. 

Permit  me  to  express  my  admiration  of  the  work  you  have  done  and  are 

doing. 

Professor  William  P.  Ddrfee, 
Hohart  College. 


3Q  Extracts  from 

Let  me  assure  you  that  we  are  all  grateful  for  what  Clark  University  is  do- 
ing for  sound  education  in  this  country,  and  I  can  only  hope  that  you  may  have 
many  successful  years  in  the  development  of  the  work  which  you  are  doing. 

S.  T.  DuTTOx,  Brookline,  Mass., 

Superintendent  of  Schools. 

In  the  opinion  of  many  who  have  studied  there,  the  peculiar  advantage  of 
Clark  University  is  mainly  attributable  to  the  close  and  personal  relations 
between  professors  and  students  under  which  the  work  is  conducted.  The 
formal  lecture  delivered  to  a  body  of  men  in  the  class-room  has  but  little  of  the 
stimulative  force  imparted  by  a  conversational  discussion  with  the  man  alone  in 
the  lecturer's  private  study,  and  too  great  praise  can  hardly  be  given  to  the 
members  of  the  faculty  of  Clark  for  their  constant  and  generous  sacrifice  of  time 
to  this  most  helpful  method  of  instruction.  The  frequent  assignment  through- 
out the  course  of  problems  involving  research  leads  to  the  best  of  training  for 
the  later  performance  of  original  work,  and  the  presentation  in  the  lecture-room 
of  the  results  thus  obtained  gives  experience  in  the  work  of  the  lecturer.  In 
perhaps  no  other  institution  are  these  methods  of  the  personal  conference  and 
the  "colloquium"  so  constantly  applied;  no  doubt  such  methods  are  impossible 
in  most  larger  universities  at  present ;  and  one  can  hardly  imagine  such  a  course 
followed  with  more  kindness  and  devotion  at  any  time  than  is  now  the  case  at 
Clark. 

Professor  Frederick  C.  Ferry, 
Williams  College. 

I  take  this  means  of  expressing  my  interest  in  the  noble  success  of  the 
University,  and  of  wishing  it  continuance  and  increase. 

Rabbi  Charles  Fleischer, 
Boston,  Mass. 

Congratulating  you  and  the  University  upon  these  years  of  achievement, 

Alice  C.  Fletcher, 

Washington,  D.  G. 

I  rejoice  in  the  prosperity  of  your  institution  because  it  is  one  which  sends 
forth  its  light,  not  only  for  the  few,  but  for  the  many. 

President  Wm.  Goodell  Frost, 
Berea  College. 

Though  my  stay  with  you  was  short,  yet  it  meant  the  inspiration  that  took 
me  abroad  and  pushed  me  on  to  undertake  important  work. 

Professor  John  P.  Fruit, 

William  Jewell  College. 


Congratulatory  Letters.  37 

The  Johns  Hopkins  University  sends  its  cordial  greetings  to  the  President, 
the  Trustees,  and  the  Faculty  of  Clark  University,  on  the  completion  of  its  first 
decennium,  with  congratulations  upon  its  successful  maintenance  of  high  ideals, 
and  with  best  wishes  for  its  continued  prosperity  and  power. 

President  Daniel  C.  Gilman. 

I  must  add  my  congratulations  on  the  success  of  your  work,  and  my  good 
wishes  for  its  continuance  on  even  a  larger  scale. 

Professok  George  L.  Goodale,  . 

Harvard  University. 

Every  educator  especially  owes  a  debt  of  gratitude  to  Clark  for  the  fearless 
work  it  has  done  in  breaking  down  blind  prejudice  and  advancing  the  truth. 

Professor  John  Y.  Graham, 

University  of  Alabama. 

You  have  certainly  arranged  a  most  dignified  and  impressive   series   of 

lectures  —  wholly  congruous  with  the  work  which  you  have  been  doing  during 

the  decade. 

Professor  Edward  H.  Griffin, 

Johns  Hopkins  University. 

You  will  please  accept  the  assurance  that  I  am  very  glad  indeed  that  your 
institution,  which  has  already  done  so  much  for  the  cause  of  progressive  educa- 
tion, has  thus  shown  its  vitality  and  power  of  endurance.  No  doubt  these  ten 
years  have  meant  much  struggle  and  anxiety  on  the  part  of  those  whose  heart 
was  in  the  work.  Others  may  be  able  to  express  their  appreciation  of  this  work 
with  greater  eloquence,  but  none  can  be  more  sincere  and  thankful  than  I  am. 
Truly,  if  there  is  such  a  thing  as  a  science  of  education  in  this  country  now, 
Clark  University  .  .  .  (has)  contributed  the  largest  share  toward  this  accom- 
plishment. To  me  (its)  work  has  meant  an  awakening  and  uplifting  hardly 
equalled  by  any  other  influences  that  have  worked  upon  my  soul.     May  your 

anniversary  week  be  a  thorough  success. 

Professor  M.  P.  E.  Grossmann, 
Milwaukee.,  Wis. 

Allow  me  to  extend  cordial  congratulations  on  the  auspicious  event. 

Professor  Charles  W.  Hargitt, 

Syracuse  University. 

I  extend  for  the  University  of  Maine  hearty  congratulations,  and  wish  con- 
tinued prosperity  for  the  future. 

President  A.  W.  Harris, 

University  of  Maine. 


38  Extracts  from 

I  send  you  my  hearty  congratulations  on  your  decennial  celebration. 

President  Walter  L.  Hervet, 

Teachers'  College,  Neio  York  City. 

I  congratulate  you  and  the  Trustees  and  Faculty  upon  these  successful  years 
of  your  University  work,  and  upon  this  most  appropriate  mode  of  celebrating 
the  anniversary.  It  is  a  mode  worthy  of  universal  following,  and  will,  without 
doubt,  be  more  and  more  adopted  by  our  institutions  of  higher  learning. 

Professor  G.  H.  Howison, 

University  of  California. 

Allow  me  to  offer  my  congratulations  to  you  especially,  and  to  your  associ- 
ates, for  the  marked  success  which  has  attended  the  career  of  Clark  University. 
We  have  felt  that  it  not  only  increases  the  resources  of  high  education  for 
youth,  but  it  stands  for  progress  and  enlightenment  in  the  commonwealth  and 
the  country  at  large.  There  is  a  justifiable  pride  on  the  part  of  those  who  love 
earnestness  and  progress  in  educational  matters,  as  they  review  the  past  of  this 
institution,  into  whose  good  name  and  wide  scope  of  influence  you  have  thrown 
so  much  of  your  personal  enthusiasm  as  well  as  your  scholarly  ability. 

Rev.  Edward  A.  Horton, 
Boston,  Mass. 

I  have  many  pleasant  memories  of  a  year's  profitable  work  at  Clark,  and 
rejoice  in  the  continued  success  of  Clark  University. 

Professor  L.  S.  Hulburt, 

Johns  Hopkins  University. 

The  programme  presented  is  most  attractive  and  inspiring.  I  congratulate 
you  upon  the  successful  work  of  the  past  ten  years. 

Dr.  Henry  M.  Hdrd,  Baltimore,  Md., 
Superintendent  Johns  Hopkins  Hospital. 

I  can't  help  expressing  to  you  my  feeling  of  satisfaction,  and  repeating  the 
satisfaction  I  heard  such  men  as  Cattell,  Eoyce,  Van  Gieson,  Mtinsterberg,  and 
Putnam  express,  with  the  excellent  good  taste  and  refinement  of  your  little 
celebration.  All  the  refinements  of  the  world  seem  now  to  take  refuge  in  the 
smaller  things ;  the  bigger  ones  are  getting  too  big  for  any  virtue  to  remain  with 
them.     You  have  done  something  original  and  succeeded  perfectly,  from  the 

point  of  view  of  the  passive  "  assistant." 

Professor  William  James, 
Harvard  University. 

I  beg  you  to  accept  my  heartiest  congratulations.  Each  year,  I  sincerely 
believe,  finds  me  more  grateful  and  appreciative  of  the  privileges  I  enjoyed  at 


Congratulatory  Letters.  39 

Clark,  and  especially  do  I  realize  more  and  more  what  you  yourself  did  for  me. 
I  trust  you  may  be  spared  health  and  vigor  many  years  to  come  in  your  labor, 
for  you  are  doing  a  great  work. 

George  E.  Johnson,  Andover,  Mass., 
Superintendent  of  Schools. 

I  have  been  very  deeply  interested  in  the  work  of  Clark  University,  and  in 
the  way  it  has  held  to  its  high  purposes  regardless  of  pressure  of  all  sorts  in 
other  directions.  .  .  .  Stanford  congratulates  Clark  on  ten  years'  noble  work 
for  high  thought  and  accurate  investigation. 

Pkesident  David  S.  Jokdan, 

Leland  Stanford  Jr.  University. 

For  myself  and  all  the  staff  of  the  University  of  California,  I  send  you 
hearty  congratulations  and  good  wishes.  You  have  not  attempted  to  do  as 
many  things  as  some  other  universities,  but  what  you  have  attempted  you  have 
done  exceedingly  well.  If  excellent  work  is  the  standard  of  true  success,  you 
have  been  successful  among  the  foremost. 

May  your  achievements  and  your  reputation  gain  still  greater  lustre,  and 
your  educational  work  confer  still  larger  benefits  on  succeeding  generations. 

President  Martin  Kellogg, 

University  of  California. 

May  I  say  that  I  think  you  have  taken  a  most  admirable  course  in  the  char- 
acter of  this  celebration,  and  that  I  wish  you  every  success,  not  only  on  this 
occasion,  but  in  all  the  future  years  of  the  University. 

Professor  J.  S.  Kingsley, 
Tufts  College. 

I  regret  more  than  I  can  express  my  inability  to  be  present  at  the  decennial 
celebration  of  your  noble  institution,  and  to  hear  the  splendid  series  of  lectures 

which  you  have  provided. 

Professor  Joseph  LeConte, 

University  of  California. 

It  is  a  pleasure  to  me  to  join  in  the  celebration  of  the  first  decade  of  Clark 
University.  The  method  of  celebrating  the  event  is,  I  think,  exceedingly  fit- 
ting. I  enjoyed  several  of  the  most  interesting  years  of  my  life  in  the  lecture- 
rooms  and  laboratories  of  Clark,  and  always  recall  them  with  great  satisfaction. 

Professor  J.  S.  Lemon,  Washington,  D.  C.  , 

Columbian  University. 

Clark  University  stands  unique  among  the  universities  of  this  country  in  the 
work  which  it  is  attempting  to  do.     No  other  institution  has  done  more  in  the 


40  Extracts  from 

line  of  original  investigation,  nor  given  during  the  same  period  greater  inspira- 
tion to  the  educators  of  the  country. 

Professor  G.  W.  A.  Lucket, 
University  of  Nebraska. 

Permit  me  to  congratulate  heartily  the  President,  Trustees,  and  the  Faculty 
of  Clark  University  upon  the  completion  of  the  tenth  academic  year  of  the 

University. 

President  George  E.  MacLean, 
University  of  Nebraska. 

We  appreciate  the  great  ■work  done  by  Clark  University,  and  send  every  best 

wish  for  the  future. 

President  James  G.  K.  McClure, 
Lake  Forest  University. 

I  have  the  highest  feelings  of  regard  for  Clark  University,  for  I  feel  that  I 
owe  much  to  it.  Its  conception  is  the  broadest  and  best  of  all  our  institutions, 
and  I  hope  the  time  will  come  when  it  can  broaden  out,  and,  all  obstacles 
being  removed,  go  on  to  its  full  completeness. 

Professor  William  S.  Miller, 
University  of  Wisconsin. 

When  one  thinks  of  the  amount  of  light  that  has  spread  from  Clark  Univer- 
sity and  of  the  place  that  it  fills  in  American  education  to-day,  it  is  hard  to 
realize  that  no  such  institution  was  in  existence  ten  years  ago.  Please  accept 
my  most  sincere  congratulations  to  this  auspicious  event,  with  the  hope  that  a 
long  series  of  years  of  vigorous  activity  may  be  granted  to  you,  so  that  you  may 
lead  the  University  to  ever  new  achievements,  and  continue  to  benefit  the  cause 
of  education  in  the  future,  as  you  have  so  splendidly  done  in  the  past.      Vivat, 

Jloreat,  crescat. 

Professor  F.  Monteser, 

Neio  York  University. 

It  is  with  very  great  regret  that  I  find  it  impossible  to  attend  the  rich  cele- 
bration you  have  prepared  for  the  friends  of  Clark  University  and  of  all  the 
forward  movements  in  science  for  which  you  have  made  Clark  University  stand, 
and  wish  the  University  long-continued  and  increasing  prosperity. 

Professor  E.  H.  Moore, 
University  of  Chicago. 

My  participation  in  the  treasures  you  offered  was  thus  limited  to  one  day  — 
but  this  one  day,  with  the  three  lectures  I  listened  to,  and  the  very  interesting 
men  I  met,  was  so  agreeable  and  valuable  that  I  feel  the  desire  to  thank  you 
warmly  for  the  distinguished  and  exquisite  pleasure.  I  take  special  pleasure 
in  combining  with  my  personal  thanks  my  congratulations  to  the  high  success 


Congratulatory  Letters.  41 

of  the  celebration  and  my  very  best  wishes  for  the  next  ten  years  in  the  life  of 

Clark  University. 

Professor  Hugo  Munsterberg, 
Harvard  University. 

Permit  me  to  express  here  my  sincere  admiration  and  respect  for  the  aims, 
ideals,  and  plans  of  Clark  University ;  these  are  of  such  an  ideal  character  that 
they  are  bound  to  interest  profoundly  every  man  who  loves  science  for  its  own 

sake. 

Professor  J.  U.  Nef, 

University  of  Chicago. 

Permit  me  to  offer  my  hearty  congratulations  on  the  work  done  and  the 
progress  made  in  the  ten  years  of  Clark's  existence,  to  express  the  hope  that  the 
future  may  be  marked  by  even  greater  achievements. 

President  Ctrus  Northrop, 

University  of  Minnesota. 

Clark  University  does  well  to  celebrate  in  such  a  becoming  manner  the  noble 
service  which  she  has  rendered  to  higher  education  in  this  country.  May  the 
next  ten  years  be  no  less  fruitful  and  helpful  to  those  who  have  become 
accustomed  to  look  to  Clark  University  for  inspiration  and  guidance. 

Professor  F.  W.  Osborx, 

Adelphi  College,  Brooklyn,  JSf.  Y. 

I  write  to  congratulate  you  most  cordially  upon  your  celebration  of  the  com- 
pletion of  the  tenth  academic  year  of  Clark  University. 

Professor  Henry  F.  Osborn, 

Columbia  University. 

Allow  me  to  congratulate  you  upon  these  lectures,  and  also  upon  the  remark- 
able results  which  you  have  been  able  to  accomplish  in  ten  years  in  connection 

with  Clark  University. 

Professor  G.  T.  "W.  Patrick, 

University  of  Iowa. 

The  Provost,  Trustees,  and  Faculty  of  the  University  of  Pennsylvania 
present  their  cordial  congratulations  to  the  President,  Trustees,  and  Faculty  of 
Clark  University  on  the  happy  completion  of  the  tenth  academic  year  of  the 
University. 

The  President,  Trustees,  and  Faculty  of  Clark  University  certainly  deserve 
the  thanks  of  all  those  interested  in  the  cause  of  education. 

Professor  George  H.  Price, 

Vanderbilt  University. 


42  Extracts  from 

Pray  accept  congratulations  on  the  completion  of  a  decade  of  grand  work, 
and  on  the  prospects  of  even  better  work  for  the  future. 

John  T.  Prince,  West  Newton,  Mass., 
Agent  State  Board  of  Education. 

I  send  my  heartiest  congratulations  on  the  great  achievements  of  Clark 
University  during  its  first  decade,  and  express  my  sincerest  desire  that  its  use- 
fulness may  continue  and  expand  for  many  centuries  to  come. 

Professor  Ernst  Richard, 

New  York  City. 

President  H.  W.  Kogers  (Northwestern  University)  desires  to  extend  the 
congratulations  of  Northwestern  University,  as  well  as  his  own,  upon  the  great 
success  of  Clark  University  and  the  distinction  it  has  attained  in  the  academic 
world. 

James  E.  Eussell  (Dean,  Teachers'  College,  New  York)  wishes  to  convey 
to  the  President  of  the  University  his  best  wishes  for  the  continued  success 
and  prosperity  of  the  institution. 

President  L.  Clark  Seelte  (Smith  College)  offers  his  hearty  congratula- 
tions on  the  important  educational  work  it  has  already  accomplished. 

With  sincere  thanks  and  hearty  congratulations  on  the  auspicious  occasion, 

Professor  James  Seth, 

Columbia  University. 

Meanwhile  I  wish  to  join  in  the  many  congratulations  I  am  sure  you  will 
receive  upon  the  quiet  and  dignified,  but  none  the  less  eminent,  manner  in  which 
Clark  University  has  carried  on  the  work  of  the  past  decade,  and  upon  the 
manner  in  which  it  has  reflected  honor  upon  American  scholarship  in  science 
and  philosophy. 

Albert  Shaw,  New  York,  N.  Y., 
Editor  Beview  of  Beviews. 

We  shall  always  be  grateful  for  the  work  that  has  already  been  accomplished 
by  the  University,  and  especially  for  the  ideals  which  it  has  brought  to  the 
colleges  and  universities  of  the  West.     With  high  personal  regard  and  warmest 

congratulations  from  our  faculty. 

President  William  F.  Slocum, 
Colorado  College. 

With  best  wishes  for  the  success  of  the  celebration  and  for  the  continued 
prosperity  of  your  institution, 

President  F.  H.  Snow, 

University  of  Kansas. 


Congratulatory  Letters.  43 

Allow  me  to  congratulate  the  University  upon  its  happy  completion  of  ten 
years'  life  and  work,  and  to  wish  it  a  long  and  prosperous  future. 

Professor  Frederick  Starr, 
University  of  Chicago. 

I  wish  to  send  my  cordial  congratulations  and  my  wish  that  the  next  ten 
years  may  witness  the  coming  to  the  University  of  such  ample  endowments 
as  will  enable  it  to  accomplish  its  high  ideals. 

President  James  M.  Taylor, 
Vassar  College. 

Please  accept  my  best  wishes  for  continued  prosperity. 

President  W.  O.  Thompson, 

Ohio  State  University. 

I  do  not  like  to  let  the  present  occasion  pass  without  intimating  to  you  my 

appreciation  and  admiration  of  the  methods  and  aims  of  university  work  for 

which  Clark  University  has  stood  in  the  past,  and  will,  I  hope,  stand  in  a 

long  and  prosperous  future.     My  recent  visit  to  Worcester  merely  confirmed  a 

belief  which  I  have  long  held,  —  that  the  type  of  man  that  Clark  University 

calls  to  its  professorial  chairs,  and  the  type  of  man  that  it  sends  into  active  life 

at  the  close  of  its  three  or  four  years  of  graduate  study,  are  types  that  represent 

the  highest  ideal  of  scholarship,  and  are  the  very  salt  of  American  society.     I 

hope,  most  sincerely,  that  the  coming  celebration  will  prove  to  be  the  door 

through  which  you  and  the  University  pass  to  greatly  extended  activity  upon 

your  own  high  level. 

Professor  E.  B.  Titchener, 

Cornell  University. 

I  wish  to  express  my  sincere  appreciation  of  the  service  to  education  and 
investigation  which  Clark  University  is  thus  undertaking,  a  service  which  is 
eminently  in  harmony  with  the  work  of  Clark  University  from  the  beginning. 

Professor  James  H.  Tufts, 
University  of  Chicago. 

I  wish  to  extend  my  hearty  congratulations  on  the  successful  work  of  the 
University  during  the  last  ten  years,  and  ray  best  and  most  hearty  good  wishes. 

Professor  John  M.  Tyler, 
Amherst  College. 

Professor  Henry  B.  Ward  (University  of  Nebraska)  extends  to  the 
President,  Trustees,  and  Faculty  his  congratulations  upon  the  occasion,  and 
best  wishes  for  the  continued  success  of  the  institution. 


44  Extracts  from  Congratulatory  Ldiers. 

I  express  my  sincere  congratulations. 


Professor  Sho  Watase. 

University  of  Chicago. 

With  best  wishes  for  the  success  of  the  University, 

Professor  J.  B.  Weems, 
Iowa  State  College. 

Please  accept  congratulations  upon  the  honorable  record  of  these  ten  com- 
pleted years.     The  distinguished  service  of  yourself  and  the  University  have 

made  the  whole  world  your  debtor. 

President  B.  L.  Whitman,  Washington,  D.  C, 
Columbian  University. 

The  Clark  University  ideal  as  I  understood  it,  when  connected  with  its 
early  work,  is  the  ideal  which  I  place  above  any  others  thus  far  proposed,  and 
I  hope  that  it  may  find  strong  friends  to  help  it  forward. 

Professor  Charles  0.  Whitman, 
University  of  Chicago. 

Professor  A.  W.  Wright  (Yale  University)  sends  congratulations  and 
best  wishes  for  the  prosperity  of  the  University. 


DECENNIAL   ADDRESS. 

By  G.  Stanley  Hall,  President  of  the  University. 

It  has  been  said  that  decades  are  the  best  periods  for  studying  historic 
tendencies  because  they  are  long  enough  to  contain  a  rich  array  of  facts 
and  events,  and  short  enough  to  be  grasped  by  a  single  mind  in  the  stage 
of  its  prime.  The  ten  years  since  Clark  University  was  opened,  the  close 
of  which,  by  the  cooperation  of  a  few  beneficent  public-spirited  citizens  of 
Worcester,  we  have  sought  to  mark  in  a  very  quiet  but  dignified  way  that 
should  befit  at  once  its  size  and  its  quality,  constitute  distinctly  the  most 
important  decade  in  the  educational  history  of  this  country.  The  mere 
index  of  a  few  of  the  well-known  and  accomplished  facts  of  these  years 
has  an  eloquence  beyond  all  words.  They  have  witnessed  the  establish- 
ment of  the  Catholic  University  at  Washington,  with  its  strong  faculty 
and  its  handful  of  picked  graduates  from  the  seventy  Catholic  colleges 
of  the  country,  the  only  university  in  the  land  besides  Clark  devoted 
solely  to  graduate  work,  an  institution  related  to  us,  not  only  by  a 
strong  tie  of  sympathy  in  the  struggle  and  sacrifice  for  ideals  and  high 
standards,  but  by  my  own  long  and  personal  friendship  with  the  first 
rector,  and  by  the  fact  that  its  present  head  was  our  Worcester  neighbor 
and  kindly  friend.  The  Leland  Stanford  University,  now  one  of  the 
richest  in  the  world,  was  planned  and  endowed  by  a  long-time  friend  of 
our  Founder,  and  the  wife  of  that  founder  lately  told  me  that  she  still 
counts  ours  among  her  wisest  and  most  trusted  advisers.  The  University 
of  Chicago,  with  possibilities  of  increase  brighter  and  larger  than  any 
other,  from  the  very  first  the  most  rapid  academic  growth  in  history,  has 
leaped  into  existence  with  a  Minerva-like  completeness,  owing  in  no  small 
part  its  first  impulse  to  higher  creative  work  in  science  to  the  sagacity  of 
the  chief  trustee  of  its  Ogden  Fund,  our  fellow-townsman,  Andrew  H. 
Green,  and  which  is  still  more  closely  affiliated  to  us  by  the  fact  that  so 
many  of  the  leading  members  of  its  faculty  honored  us  by  doing  three 
years  of  their  best  work  here,  and  for  which  we  still  cherish  a  little  of 

45 


46  Decennial  Address. 

the  feeling  of  a  poor  but  proud  and  noble  mother  for  her  great  son.  The 
new  Methodist  University  at  Washington  has  begun  the  unfoldment  of 
large  and  well-matured  plans,  for  the  fulfilment  of  which  the  vitality  of 
the  strong  religious  body  behind  it  is  perhaps  the  best  of  guarantees. 
The  millions  already  provided  and  about  to  be  expended  at  the  State 
University  of  California  which  will  involve  transformation  and  enlarge- 
ment perhaps  greater  than  all  that  has  hitherto  been  done  there,  very 
comprehensive  and  valuable  as  that  is  ;  the  magnificent  new  architectural 
installation  at  Columbia  and  the  federation  of  so  many  other  affiliated 
institutions  about  it,  with  all  the  possibilities  of  our  greatest  metropolis 
open  before  it  ;  the  steady  development,  whether  for  good  or  for  ill,  of 
the  plan  of  a  great  national  university,  to  which  at  least  all  state,  if  not 
private,  colleges  and  universities  may  be  tributary  as  feeders,  and  which 
shall  command  all  the  vast  resources  of  science  in  Washington,  unify 
them,  and  add  the  new  vitalizing  function  of  research  and  perhaps  teach- 
ing, a  scheme  that  has  enlisted  most  of  the  educational  leaders  of  the 
land  and  is  sure  of  eventual  fulfilment,  —  such  are  some  of  the  events 
which  have  seemed  to  many  to  threaten  the  academic  preeminence  of 
New  England,  and  even  of  the  East,  in  the  future  ;  that  have  stirred  to 
their  very  foundations  the  older  and  more  conservative  institutions,  and 
caused  transformations  not  all  apparent  from  the  outside,  but  which 
involve  hardly  less  than  an  ultimate  revolution  of  academic  sentiments, 
methods,  and  ideals.  Fellowships,  not  for  the  indigent  who  need  support 
while  preparing  for  the  professions,  but  to  give  leisure,  opportunity,  and 
incentive  for  full  development  to  talent,  the  choicest  of  all  national  prod- 
ucts ;  research,  with  books,  apparatus,  above  all,  leaders  competent  to 
guide  and  inspire  ;  new  post-graduate  departments  for  non-professional 
specialization,  with  their  own  laboratories  and  libraries  ;  seminaries  where 
experts  discuss  the  latest  literature,  best  methods,  instruments,  and 
results  of  investigation  ;  new  journals  devoted  to  the  speedy  publication 
of  such  studies ;  new  chairs  and  topics  ;  a  growing  and  ever  widening 
distinction  between  receptive  learning  and  active  creation,  —  these  and  the 
gradual  completion  of  a  system  that  is  truly  national,  and  has  not  its 
apex  in  Europe,  where  hundreds  of  our  graduates  still  go  yearly  to  get 
what  it  should  be  a  matter  of  simple  patriotism  to  supply  at  home,  must 
suffice  to  mark  the  direction  and  progress  of  these  years  in  which  institu- 
tions and  work  alike  are  becoming  more  and  more  plastic  to  the  changing 
and  ever  more  imperative  needs  of  learning  and  science  which  have  them- 


Decennial  Address.  47 

selves  celebrated  triumplis  during  the  decade  which  could  not  even  be 
enumerated  within  the  hour.  It  is  no  wonder  that  many  old  academic 
problems  have  become  obsolete  and  new  ones  have  arisen,  and  that  pres- 
ent demands  in  men,  methods,  and  instruments  have  changed  from  those 
of  ten  years  ago. 

Again,  within  this  time  a  wave  of  doubt  and  opposition  to  the  public 
support  of  intermediate  education  passed  over  the  country,  but  the  reac- 
tion against  that  tendency  has  made  the  last  few  years  preeminently  the 
age  of  high  schools.  More  and  statelier  buildings  than  ever  before, 
longer  courses  and  more  of  them,  many  modifications  suggested  by 
committees  and  others,  great  increase  in  the  number  of  students,  rich 
and  well-planned  departures  like  the  Tome  Institute,  Mrs.  Emmons 
Blaine's  new  normal  foundation,  and  several  others  contemplated  or 
assured  but  not  yet  established,  the  new  associations  of  high  schools 
and  colleges  covering  now  all  sections  of  the  country,  the  ever  increas- 
ing collegiate  character  of  the  work  done  in  such  institutions,  and  the 
consequent  development  of  a  distinct,  and  in  some  places  urgent,  small 
college  problem,  —  all  this  shows  that  even  secondary  education,  the  last 
stage  to  be  reached  by  reforms,  has  here  been  stirred  and  quickened  as 
never  before. 

If  we  extend  our  view  to  lower  grades,  we  find  all  plastic  and  chang- 
ing. This  stronghold  of  conservatism  is  invaded  by  the  spirit  of  reform, 
often  revolution,  and  sometimes  even  of  rather  wild  experimentation. 
New  journals,  pedagogical  chairs,  new  methods,  the  new  school  hygiene, 
broader  views  that  relate  teaching  to  all  the  great  problems  of  science, 
statescraft,  and  religion,  have  arisen,  which  have  brought  the  university 
and  kindergarten  and  all  between  them  into  an  organic  unity,  yet  fitting 
all  features  of  the  system  to  the  vast  variety  of  individual  differences  of 
character,  temperament,  and  ability.  In  this  field,  I  think,  the  closing 
decade  has  witnessed  a  change  greater  than  the  preceding  quarter  of  a 
century.  New  and  better  minds  are  enlisted,  educational  topics  are  of 
increasingly  central  interest  in  the  press  and  more  dominant  in  the 
church  and  pulpit,  education  is  becoming  more  professional  and  scientific, 
recognizing  the  necessity  of  expert  leadership  and  mastery,  and  is  at  last 
assuming  its  rightful  and  larger  power,  and  its  normal  basal  all-condition- 
ing place  as  at  bottom  a  biological  science,  revealing  to  us  how  state, 
church,  home,  literature,  science,  art,  and  all  else  have  their  ultimate 
justification  only  in  so  far  as  they  are  effective  in  bringing  human  beings 


48  Dece7i7iial  Address. 

to  the  ever  fuller  maturity  of  mind  and  body  on  which  civilization  de- 
pends, and  which  it  is  the  work  of  education  to  accomplish  in  the  world. 
This  is  increasingly  necessary  as  our  country  grows  in  population  and  in 
territorial  expansion,  and  educational  progress  is  coming  to  be  recognized 
by  history  as  the  chief  standard  by  which  to  test  all  other  advancement. 
Europe  has  progressed  during  this  decade,  although  with  less  rapidity, 
along  nearly  all  these  lines,  and  the  next  decennial  promises  not  less,  but 
more  advance.  In  such  a  time  it  is,  indeed,  glorious  to  be  alive,  and  to 
be  young  is  heaven,  for  hope  is  even  brighter  than  memory. 

No  time  in  the  history  of  the  country  could  have  been  more  favorable 
than  the  beginning  of  this  period  for  a  great  and  new  university  founda- 
tion. The  epoch-making  work  of  the  Johns  Hopkins  University,  which 
for  the  preceding  decade  had  made  Baltimore  the  brightest  spot  on  the 
educational  map  of  the  country,  and  was  the  pioneer  in  the  upward  move- 
ment, had  leavened  the  colleges  and  roused  them  from  the  life  of  mo- 
notony and  routine  which  then  prevailed,  and  kindled  a  strong  and 
widespread  desire  for  better  things.  The  significance  of  the  work  of 
that  institution  can  hardly  be  overestimated.  But  financial  clouds  had 
already  begun  to  threaten  this  great  Southern  luminary,  and  there  were 
indications  that,  if  the  great  work  it  had  begun  was  to  be  carried  on, 
parts  of  it,  at  least,  must  be  transplanted  to  new  fields. 

It  was  at  this  crisis  that  our  munificent  Founder  entered  the  field  with 
the  largest  single  gift  ever  made  to  education  in  New  England,  and  one 
of  the  largest  in  the  world,  and  with  the  offer  of  more  to  come,  if  suffi- 
cient cooperation  was  forthcoming.  He  selected  Worcester  as  the  site 
of  his  great  enterprise  with  a  piety  to  the  region  of  his  nativity  worthy  of 
the  greatest  respect  and  emulation,  and  in  addition  to  the  fulfilment  of 
his  pledges  gave  it  the  benefit  of  his  own  previous  wide  studies  of  educa- 
tion in  Europe,  and  contributed  wisely  matured  plans  and  constant  per- 
sonal oversight  and  labor  for  years.  It  is  as  strenuously  engaged  in  this 
highest  of  all  human  endeavors  that  the  world  knows  him,  and  that  we 
shall  remember  him,  and  I  am  sure  that  we  all  unite  to-day  first  of  all 
in  sending  him  in  the  retirement  his  health  demands  (although  it  cannot 
assuage  his  interest  to  see  the  work  of  his  hands  prosper)  our  most  cordial 
greetings  and  our  most  hearty  congratulations. 

With  a  dozen  colleges  within  a  radius  of  one  hundred  miles  doing 
graduate  work,  the  plainest  logic  of  events  suggested  at  once  a  policy  of 
transplanting  to  this  new  field  part  of  the  spirit  of  the  Johns  Hopkins 


Decennial  Address.  49 

University,  and  taking  here  the  obvious  and  almost  inevitable  next  step  by 
eliminating  college  work,  although  the  chief  source  of  income  by  fees  was 
thereby  also  sacrificed,  and  thus  avoiding  the  hot  and  sometimes  bitter 
competition  for  students,  waiving  the  test  of  numbers,  and  being  the  first 
upon  the  higher  plane  of  purely  graduate  work,  selecting  rigorously  the 
best  students,  seeking  to  train  leaders  only,  educating  professors,  and  ad- 
vancing science  by  new  discoveries.  It  was  indeed  a  new  field  wide  open 
and  inviting,  the  cultivation  of  which  was  needed  to  complete  our 
national  life  ;  the  preliminary  stages  of  its  occupancy  all  finished,  yes, 
necessary  almost  as  a  work  of  rescue  for  the  few  elite  graduates  who 
wished  to  go  beyond  college  but  not  into  any  of  the  three  professions, 
and  who  had  had  hitherto  a  pathetically  hard  time.  The  call  to  the 
President  gave  assurance  of  the  highest  aims  and  of  perfect  academic 
freedom,  a  pledge  that  has  been  absolutely  kept.  He  was  sent  to  Europe 
a  year  on  full  pay  to  learn  the  best  its  institutions  could  teach,  and  the 
Faculty  that  first  fore-gathered  here  has  never  been  excelled  in  strength, 
if  indeed  it  has  ever  been  equalled  anywhere  for  its  size.  Story,  an 
instructor  at  Harvard,  colleague  and  friend  of  Sylvester,  formerly  acting 
editor  of  the  chief  mathematical  journal  of  the  country  and  co-head  of  his 
department  at  Baltimore,  founder  of  another  journal  here,  who  has 
enriched  his  department  by  contributions,  the  list  of  which  printed  else- 
where in  this  volume  tells  its  own  story ;  Michelson,  who  while  here 
accepted  an  invitation  of  the  French  Government  to  demonstrate  in  Paris 
his  epoch-making  discoveries  in  the  field  of  light,  which  he  did  while  on 
our  pay-roll  —  lately  especially  honored  by  learned  societies  at  home  and 
abroad,  now  head  of  one  of  the  best-equipped  and  largest  laboratories  in 
the  world,  and  still  continuing  his  brilliant  contributions  to  the  sum  of 
human  knowledge  ;  Whitman,  now  head  of  another  great  university 
laboratory,  trainer  of  many  young  professors,  founder  and  editor  of 
the  best  and  most  expensive  biological  journal,  head  of  Woods  HoU 
marine  laboratory  and  summer  school,  one  of  the  best  of  its  kind  in  the 
world,  himself  a  contributor  to  his  science ;  Michael,  than  whom  America 
had  not  produced  a  more  promising  or  talented  chemist,  the  list  of 
whose  published  works  would  be  far  too  long  to  read  here ;  Nef,  perhaps 
our  most  brilliant  young  chemist,  and  now  head  of  one  of  the  largest 
and  best-equipped  laboratories  in  the  world,  and  with  a  power  of  sus- 
tained original  work  rarely  excelled ;  Mall,  now  full  professor  at  the 
Johns  Hopkins  University,  and  head  of  the  great  new  anatomical  labora- 


50  Decennial  Address. 

tory  and  museum  there,  whose  published  contributions  are  admirable 
illustrations  of  both  the  great  caution  and  boldness  needed  by  a  student 
in  his  field ;  Boas,  the  leading  American  in  physical  anthropology,  now 
a  professor  at  Columbia ;  Loeb,  almost  the  first  expert  that  this  country 
could  boast  in  the  new  physical  chemistry  in  the  sense  of  Ostwald,  now 
head  of  his  department  in  the  University  of  the  city  of  New  York ; 
Bolza,  an  almost  ideal  teacher,  suggesting  the  great  Kirchoff  in  the  per- 
fection of  his  demonstrations ;  the  brilliant  and  lamented  Baur,  leader 
of  the  expedition  to  the  Galapagos  Islands  made  possible  by  the  gift  of 
Worcester's  patron  saint  of  so  many  good  enterprises,  Mr.  Salisbury; 
Donaldson,  now  dean  of  the  graduate  school  of  the  University  of 
Chicago,  author  of  the  best  handbook  in  English  on  the  brain,  with 
a  caution,  poise,  and  diligence  befitting  the  successful  investigator  in  that 
dangerous  but  fascinating  field ;  MuUiken,  suddenly  placed  in  a  position 
of  great  diificulty,  discharged  its  duties  with  rare  ability  and  discretion 
for  one  so  young ;  Lombard,  now  professor  in  Michigan,  genial,  assiduous, 
a  gifted  teacher  and  enthusiastic  student ;  White,  scholarly,  able,  a  born 
teacher  and  student ;  McMurrich,  an  untiring  investigator  and  a  lucid 
inquirer  after  knowledge ;  those  now  here,  who  have  since  become  so 
well-known,  Burnham,  Chamberlain,  Hodge,  Perott,  Sanford,  Taber,  and 
Webster  ;  these,  not  to  mention  many  others,  then  only  fellows,  but  who 
have  achieved  so  much  in  their  work  and  positions  since,  —  these  are  the 
men  and  others  whose  presence  on  this  spot,  whose  high  intercourse  and 
whose  stimulating  personal  contact  with  each  other,  whose  ardor  and  devo- 
tion in  the  pursuit  of  knowledge,  whose  healthful  emulation  in  achieve- 
ment, made  this  almost  classic  ground  and  the  cynosure  of  the  eyes  of 
all  those  in  this  country  who  love  science  for  its  own  sake.  With  the 
wealth,  wisdom,  and  interest  of  our  Founder,  with  the  high  character 
and  culture  of  our  Board  of  Trustees,  with  the  intelligence  of  such  a 
community  of  old  New  England,  with  an  atmosphere  of  intellectual  free- 
dom, with  unique  and  precious  exemption  from  the  drudgery  of  excessive 
teaching  and  examinations,  with  the  youth  of  the  Faculty,  none  of  whom 
had  reached  the  zenith  of  their  maturity,  with  substantial  and  ample 
buildings,  abundant  and  forthcoming  funds  for  equipment,  few  rules  and 
almost  no  discipline  or  routine  of  faculty  meetings,  the  motto  on  our  seal, 
fiat  lux,  our  university  color  white,  —  is  it  any  wonder  if  some  of  our 
young  men  saw  visions  and  dreamed  dreams,  or  perhaps  in  some  cases  fell 
in  love  with  the  highest  ideals,  or  that  the  very  memory  of  the  first  stage 


Decennial  Address.  51 

of  our  history  is  to-day,  as  it  lias  been  in  darker  hours,  a  most  precious 
memory  and  a  basis  of  an  all-sustaining  hope  ? 

To  these  days  of  our  prime  to  which  our  former  students  and  profess- 
ors recur  with  joy,  and  in  whose  breasts  the  processes  of  idealization  of 
them  have  already  begun,  days  which  were  pervaded  by  sentiments  of  joy 
and  hope  very  like  those  which  animated  the  best  years  of  the  Johns 
Hopkins  University,  we  have  often  reverted  since  in  soberer  hours  with 
longing  thoughts  of  what  might  have  been  had  the  University  continued 
in  all  its  pristine  strength.  Not  one  weak,  dull,  or  bad  man  in  our  Faculty, 
all  given  not  only  leisure,  but  every  possible  incentive  to  do  the  very  best 
work  of  which  they  were  capable,  with  a  Founder  and  a  board  of  control 
who  realized  that  a  new  endowment  should  do  new  things,  and  that  the 
best  use  of  money  is  to  help  the  best  men,  we  entered  a  field  very  largely 
new  and  with  as  bright  prospects  as  we  could  wish. 

But  life  has  its  contrasts  and  competitions.  The  reductions  of  our 
force,  which  occurred  at  the  end  of  the  third  year,  sad  to  us  almost  beyond 
precedent,  although  helpful  elsewhere,  may  be  ascribed  to  fate,  disease, 
or  to  the  very  envy  of  the  gods.  Some  incidents  should  remain  unwritten, 
but  it  should  be  known  that  our  Trustees  foresaw  from  the  beginning  of 
the  year  one  of  the  gravest  of  crises,  and  met  it  with  an  unanimity,  a 
wisdom,  and  a  firmness  which  even  in  the  light  of  all  that  has  transpired 
since,  I  think,  could  not  be  improved  on.  The  pain  of  it  all  has  faded, 
the  glad  hand  has  been  extended  and  accepted  by  nearly  if  not  quite  all 
who  left  us  ;  the  lessons  of  adversity  have  been  learned  and  laid  well  to 
heart,  and  we  hope  and  believe  that  these  and  all  their  attendant  incidents 
may  be  considered  closed. 

Although  nearly  half  our  Faculty  and  students  left  us  in  the  hegira, 
and  our  income  had  dropped  in  almost  the  same  proportion,  and  only  the 
departments  of  psychology  and  mathematics  remained  nearly  intact,  we 
fortunately  had  left  in  every  department  young  men  as  promising  as  any 
in  the  land.  They  needed  simply  to  grow,  and  never  has  there  been  such 
an  environment  for  a  faculty  to  develop  as  in  this  "paradise  of  young 
professors,"  as  a  leading  college  president  has  called  this  University.  To 
Darwin  the  greatest  joy  of  life  was  to  see  growth ;  and  to  see  the  unfold- 
ment  of  these  youthful,  intellectual  elite,  and  to  feel  the  sense  of  growth 
with  them  as  all  near  them  must,  is  a  satisfaction  almost  akin  to  the 
rapture  of  discovery  itself.  Now  the  years  have  done  their  work,  and 
our  Faculty,  although  smaller,  was  never  stronger,  never  more  prolific. 


62  Decennial  Address. 

stimulating,  and  attractive  to  students,  in  proportion  to  its  size,  than  it  is 
to-day.  There  has  never  been  such  loyalty  to  the  institution  and  its 
ideals,  such  readiness  to  endure  the  petty  and  the  great  economies  now 
necessary,  such  prompt  and  frequent  refusals  of  larger  salaries  elsewhere, 
and  so  strong  a  sentiment  that,  so  long  as  a  man  has  growth  in  him,  our 
incentive,  opportunity,  and  plan  of  work  are  of  more  value  than  a  large 
increase  of  salary. 

Tliese  changes  involved,  however,  but  little  reduction  of  the  number 
of  instructors  or  of  students,  but  materially  decreased  for  a  time  the  effi- 
ciency of  the  University.  Since  the  end  of  the  third  year  the  President, 
who  was  not  required  to  teach,  has  done  full  professorial  duty  in  addition 
to  that  of  administration,  has  established  a  seminary  at  his  house  three 
hours  each  week  through  the  entire  academic  year,  and  founded  and  con- 
ducted at  his  own  expense  a  new  educational  journal.  The  income-bear- 
ing summer  school  has  been  organized  and  conducted  during  the  past 
seven  years  with  the  active  and  efficient  coo^^eration  of  a  large  local 
advisory  board  under  the  direction  of  Colonel  E.  B.  Stoddard  and  Charles 
M.  Thayer,  Esq.,  by  which  its  social  character,  that  has  contributed 
much  to  its  success,  has  been  established  on  a  high  plane.  The  summer 
school  represents  only  the  departments  of  biology,  psychology,  and  peda- 
gogy, is  open  to  every  one  of  either  sex  on  the  payment  of  a  small  fee,  is 
popular  rather  than  technical  in  its  scientific  character,  has  been  numer- 
ously attended,  and  in  all  ways  is  directly  in  contrast  with  the  work  of 
the  year.  Hardly  a  ripple  has  marred  the  harmony  within  the  Univer- 
sity during  these  last  seven  years,  and  every  man,  student  and  instructor 
alike,  has  been  hard  at  work  and  enthusiastic  for  our  own  unique  and 
individual  method  and  plan. 

This  institution  must  be  judged  from  within  and  by  educational  and 
scientific  experts,  and  the  commendations  which  we  have  lately  received 
from  leading  specialists,  some  of  which  are  printed  elsewhere  in  this 
volume,  have  been  so  numerous,  spontaneous,  and  hearty  in  response  to 
our  invitation  to  be  present,  as  almost  to  rival  in  cordiality  and  loyalty 
to  the  now  so  definitely  developed  Clark  idea  and  Clark  spirit  tliat  of 
our  three  alumni  associations  of  the  Pacific  Coast,  Illinois,  and  Indiana 
organized  during  the  present  year. 

Scientific  work  must  be  weighed  and  not  measured,  so  that  numbers 
tell  but  little.  Clark  University  has  been  instrumental  in  training  well- 
nigh  three  hundred  professors  or  special  academic  instructors,  has  numbered 


Decennial  Address.  53 

over  twelve  hundred  different  persons  enrolled  in  its  summer  school,  not 
counting  the  hundreds  who  have  attended  more  than  one  session.  These, 
especially  the  former,  are  in  a  sense  our  epistles  known  and  read  of  all 
men.  The  other  output  of  a  university  like  ours  is  its  scientific  work, 
and  here  we  have  five  hundred  publications  based  upon  work  done  here, 
of  which  twenty-five  are  books.  The  University  now  publishes  three 
journals,  with  hope  of  a  fourth  as  a  more  permanent  way  of  marking  the 
beginning  of  its  second  decade. 

Small  as  we  are,  if  our  departments  and  students  are  measured  by  the 
significant  criterion  of  the  number  of  the  doctorates  annually  conferred 
here,  we  rank  among  the  best  and  largest  institutions  of  the  land.  Al- 
though our  fellowship  funds  have  declined,  and  that,  too,  in  the  midst 
of  a  competition,  which  never  existed  or  was  hitherto  dreamed  of,  our 
numbers  of  late  years  have  slightly  but  steadily  increased,  although  at 
the  same  time  we  could  go  on  forever  and  do  invaluable  work  of  research 
and  publication  like  the  French  Ecole  des  Hautes  Etudes,  or  a  few  other 
Old  World  institutions,  even  if  we  had  no  students ;  and,  indeed,  America 
may  need  in  the  future,  if,  indeed,  she  does  not  already,  at  least,  one  such 
academic  endowment  for  research  only.  One  thing,  at  least,  is  true  so 
far,  hardship  has  no  whit  lowered  our  aims  or  diluted  our  quality,  but  if 
anything  has  had  the  reverse  influence ;  and  I  fervently  trust  (and  think 
I  can  speak  on  this  point  with  confidence  for  the  entire  Faculty)  that  this 
may  be  the  case  throughout  all  the  infinite  future  that  endowments  like 
this  in  a  country  like  ours  have  a  right  to  expect.  Although  influences 
are  too  subtly  psychological  to  be  traced,  I  am  writing  our  history,  and 
find  it  a  most  inspiring  theme,  and  I  believe  it  adds  already  a  very  bright 
and  hopeful  page  to  the  records  of  higher  education  in  the  country,  and 
one  which  history  will  brighten  to  epochal  significance.  It  has,  on 
the  whole,  in  it  one  clear  note,  not  of  discouragement,  but  of  hope  and 
confidence. 

Have  we  duly  considered,  even  the  best  of  us,  what  a  real  university 
is  and  means,  how  widely  it  differs  from  a  college,  and  what  a  wealth 
of  vast,  new,  and  in  themselves  most  educative  problems  it  opens?  A 
college  is  for  general,  the  university  for  special,  culture.  The  former 
develops  a  wide  basis  of  training  and  information,  while  the  latter  brings 
to  a  definite  apex.  One  makes  broad  men,  the  other  sharpens  them  to 
a  point.  The  college  digests  and  impresses  second-hand  knowledge  as 
highly  vitalized   as  good   pedagogy  can  make   it,  while  the  university. 


64  Decennial  Address. 

as  one  of  its  choicest  functions,  creates  new  knowledge  by  research  and 
discovery.  The  well-furnished  bachelor  of  arts,  on  turning  from  the 
receptivity  of  knowing  to  creative ,  research,  is  at  first  helpless  as  a 
new-born  babe,  and  needs  abundant  and  personal  direction  and  encour- 
agement before  he  can  walk  alone ;  but  when  the  new  powers  are  once 
acquired  they  are  veritable  regeneration.  He  scorns  the  mere  luxury 
of  knowing,  and  wishes  to  achieve,  to  become  an  authority  and  not  an 
echo.  His  ambition  is  to  know  how  it  looks  near  and  beyond  the 
frontier  of  knowledge,  and  to  wrest  if  possible  a  new  inch  of  territory 
from  the  nescient  realm  of  chaos  and  old  night,  and  this  becomes  a  new 
and  consuming  passion  which  makes  him  feel  a  certain  kinship  with  the 
great  creative  minds  of  all  ages,  and  having  contributed  ever  so  little, 
he  realizes  for  the  first  time  what  true  intellectual  freedom  is,  and  attains 
intellectual  manhood  and  maturity.  This  thrill  of  discovery,  once  felt, 
is  the  royal  accolade  of  science,  which  says  to  the  novice,  stand  erect, 
look  about  you,  that  henceforth  you  may  light  your  own  way  with 
independent  knowledge. 

This  higher  educational  realm  is  full  of  new  "  phenomena  of  altitude." 
Faculties,  instead  of  discussing  and  elaborating  plans  for  commencement 
ceremonies,  hearing  recitations,  preparing  and  then  reading  the  results 
of  examination  papers,  and  carefully  marking  each  individual  exercise, 
grinding  in  the  old  mills  of  parietal  regulations,  discipline,  and  the  rules 
of  conduct  needful  to  civilize  the  adolescent  homo  sapiens  ferus,  revising 
requirements  for  admission,  tacking  and  shaping  the  policy  to  gather 
in  more  students  and  keep  ahead  of  others  in  the  struggle  to  get  the  best 
connections  with  high  and  fitting  schools,  are  occupied  with  far  different 
problems  wherever  the  university  spirit  has  a  true  and  real  embodiment. 
Here  first  of  all  men  must  be  discriminated,  and  great  issues  hang  upon 
the  success  in  differentiating  superior  from  indifferent  young  men.  To 
detect  the  early  manifestations  of  talent  and  genius  in  the  different  fields 
of  intellectual  endeavor,  which  some  presidents  and  professors  can,  and 
others  so  eminently  lack  the  power  to  do,  is  the  crucial  doorkeeping 
problem,  where  great  privileges  are  to  be  awarded  to  great  promise. 
This  is  almost  a  life  and  career  saving  function  for  not  only  the  young 
professors  and  students,  but  for  the  university.  Men  are  not  equal,  and 
there  must  be  a  touchstone  of  mental  aristocracy  to  discriminate  $500 
from  $10,000  men. 

Second,  having  selected  these,  the  university  should  bestow  freely  its 


Decennial  Address,  55 

needed  aid  and  equipment,  and  the  professor  his  choicest  time  and 
knowledge,  to  perfect  the  precious  environment  by  which  the  later  stages 
of  growth,  so  liable  to  be  lost,  but  on  the  full  development  of  which 
civilization  itself  hangs,  and  perfected.  How  to  select  the  best,  ripest, 
and  most  fruitful  topics  for  investigation  requires  an  almost  prophetic 
ken  in  which  differences  in  individual  professors  are  immense.  To  study 
individuals  enough  to  adapt  each  theme  to  each  personality  is  another 
problem  as  new  as  it  is  delicate  and  difficult.  The  right  solution  of  both 
these  is  the  large  half  of  the  work.  The  professor  should  give  his  best 
suggestion,  with  no  reservation  for  himself,  and  the  able  student  should 
not  be  an  apprentice  to  serve  his  master,  but  should  be  distinctly 
educated  toward  leadership  himself  from  the  first. 

Having  thus  sown  fit  seed  in  fit  soil,  it  must  be  watched  and  watered 
with  constant  suggestion.  The  best  and  newest  literature  ;  the  most 
effective  and  original  apparatus  that  can  be  devised  and  if  possible 
made  on  the  spot ;  how  to  insure  in  the  best  form  and  place  the  speedy 
publication  of  work  and  to  bring  it  under  the  eye  of  all  experts  ;  how 
to  avoid  conflict  and  duplication  ;  how  general  or  how  special  thesis  sub- 
jects and  work  should  be  to  best  combine  the  two  sometimes  more  or 
less  divergent  ends  of  discovery  and  education  ;  the  requirements  for 
perhaps  the  choicest  of  all  degrees,  the  doctorate  of  philosophy  ;  the  best 
modes  of  individual  examination  for  it ;  the  number  and  relation  of 
subjects  required  ;  the  migration  of  students  so  as  to  insure  not  only 
the  best  environment  for  each,  but  to  give  to  professors  not  only  in  the 
same  department,  but  in  different  institutions,  the  same  stimulus  that 
was  felt  when  the  elective  system  aroused  the  dry-as-dust  professors  to 
unwonted  effort  lest  their  class-rooms  be  left  vacant ;  the  kindred  ques- 
tion of  the  relative  value  of  graduate  work  at  home  and  abroad  for 
each  student  and  for  each  department ;  the  fit  federation  of  graduate 
clubs  and  their  thirty-five  hundred  members  in  the  twenty-three  Ameri- 
can institutions  now  recognized  in  the  yearbook  ;  the  great  problem  of 
printing  and  special  journals  together  with  interchange  of  monographs  ; 
the  vast  new  library  problems  of  purveying  for  highly  specialized,  but 
very  voracious,  appetites  which  make  the  true  university  librarian  a  man 
of  far  different  order  from  others,  and  gives  him  a  wealth  of  new  prob- 
lems of  exchange,  foraging,  etc.  ;  to  maintain  the  true  relations  between 
lecture  work  and  individual  guidance  while  duly  emancipating  the  pro- 
fessors from  the  drudgery  of  elementary  teaching  and  mass  treatment 


66  Decennial  Address. 

of  great  bodies  of  students  ;  the  many  and  wide-reaching  differences 
between  pure  and  applied  science,  and  the  practical  methods  by  which 
this  distinction  is  maintained  ;  the  danger  of  great  aggregations  of 
students  and  the  advantages  of  few  ;  the  wide  differences  between  the 
new  kind  of  professor  needed  in  the  university  and  those  in  the  college, 
where  no  provision  is  made  for  the  advancement  of  learning,  and  the 
tests  are  mainly  pedagogic  ;  the  even  greater  contrasts  between  scholar- 
ship funds  for  the  aid  of  poverty  to  professional  careers,  which  are  a 
doubtful  advantage  even  in  colleges  where  they  belong,  and  the  true 
university  fellowship  as  above  described  ;  the  growing  dominance  and 
need  of  expertness  in  all  fields  for  which  graduate  departments  must 
prepare  as  well  as  for  professorship  alone,  —  these  and  many  great  ques- 
tions like  them,  destined  more  and  more  to  eclipse  all  others  which  are 
just  looming  up,  and  for  the  irrigation  and  ventilation  of  which  we  hope 
to  establish  here  soon  a  new  educational  journal  —  such  questions  con- 
stitute this  opening  field  of  what  may  be  called  the  higher  educational 
statesmanship. 

The  hastiest  glance  at  the  situation  on  an  anniversary  like  this  would 
be  incomplete  unless  we  turned  toward  the  future.  Our  own  needs  here 
are  many  and  our  wants  urgent,  but  our  faith  is  firm  that  in  a  community 
like  this  the  time  will  soon  come  when  no  wills  will  be  drawn  by  wealthy 
people  without  carefully  considering  the  conclusion  of  the  largest  parlia- 
mentary report  ever  made,  which  fills  near  a  score  of  volumes,  was  many 
years  in  the  making,  and  describes  all  the  public  bequests  ever  made  in 
England.  The  substance  of  the  conclusion  of  that  most  competent  tribu- 
nal that  has  ever  spoken  upon  this  subject  is  that  the  best  of  all  uses  of 
public  benefactions  is,  not  for  charity  to  the  poor  or  even  the  sick  and  de- 
fective, noble  and  Christlike  as  those  charities  are,  not  for  lower  education 
or  religion,  beneficient  as  these  are,  but  rather  for  affording  the  very  best 
opportunities  for  the  highest  possible  training  of  the  very  best  minds  in 
universities,  because  in  training  these  the  ivhole  work  of  church,  state,  school, 
and  charity  is  not  only  made  more  efficient,  but  raised  to  a  higher  level,  and 
in  this  service  all  other  causes  are  at  the  same  time  best  advanced.  I  beg 
respectfully,  but  with  all  my  heart  and  mind,  to  urge  this  conclusion  by 
the  highest  human  authority  upon  all  those  contemplating  the  bestow- 
ment  of  funds  where  they  will  accomplish  most  for  the  good  of  man. 

Our  very  best  department  is  the  library,  which  is  so  well  endowed  that 
we  do  not  at  present  need  to  expend  the  income  of  the  fund.     In  this 


Decennial  Address.  57 

respect  the  sagacity  and  benevolence  of  our  Founder  has  been  more  than 
sufficient  for  our  needs  up  to  the  present  time,  and  our  most  efficient  and 
courteous  librarian  has  found  many  means  and  devices,  new  to  the  most 
advanced  library  science,  of  bringing  out  its  utmost  efficiency  for  our 
work,  and  of  making  it  in  all  the  pregnant  sense  of  that  word  attractive 
to  all  who  once  come  within  the  sphere  of  its  influence.  His  work  amply 
merits  all  the  growing  recognition  that  it  and  his  rare  personnel  are 
so  steadily  gaining.  His  special  report  contains  new  suggestions  and 
exjDeriences. 

The  large  and  new  demands  upon  the  Public  Library  caused  by  the 
presence  of  an  university  for  research  which  involved  a  material  addition 
to  its  work,  which  is  likely  to  increase  in  proportion  to  our  growth,  should 
be  distinctly  recognized.  The  special  privileges  needed  by  investigators 
have  often  been  a  strain  upon  the  capacity  of  both  its  officers,  its  methods 
of  administration  and  service,  and  the  resources  of  its  alcoves.  The 
Public  Library  has  on  the  whole  well  met  the  test,  and  I  desire  here  to 
express,  not  only  for  myself  personally,  but  for  the  other  members  of  the 
University  our  gratitude  to  the  city,  the  Trustees,  and  particularly  to  the 
accomplished  head  of  the  library  itself,  whose  cooperation,  with  his  able 
corps  of  assistants,  has  been  a  factor  in  an  important  part  of  our  work. 

Our  two  strongest  departments  are  mathematics  and  psychology. 
These  two,  as  has  been  often  said,  are  the  root  and  heart  of  all  other 
branches.  Mathematics  is  the  grammar  of  all  the  sciences  that  deal  with 
inanimate  nature,  and  the  study  of  the  human  mind  and  soul  opens  the 
field  where  all  animate  nature  celebrates  her  highest  triumph  and  which 
underlies  all  the  humanities.  While  we  could  expend  with  profit  much 
more  than  at  present,  perhaps  the  entire  resources  of  the  University,  upon 
these  departments,  or  perhaps,  even  upon  each  of  them,  they  are  best 
equipped  and  least  in  immediate  need.  We  have  books,  journals,  pro- 
fessors, means  of  speedy  publication,  and  well-developed  traditions,  and 
can  claim,  we  think  with  modesty,  to  be  doing  creditable  work. 

Our  greatest  and  most  pressing  need,  according  to  the  policy  first 
formulated  of  strengthening  the  departments  already  established  before 
founding  new  ones,  is  to  enlarge  the  biology  to  an  independent  position, 
with  due  provision  for  botany  and  the  related  subject  of  paleontology. 
The  foundations  of  a  building  for  this  group  of  studies  is  already  laid 
on  the  grounds,  and  its  completion,  with  an  endowment  of  $150,000  or 
$200,000  with  what  we  now  have,  would  give  us  a  strong  department  able 


58  Decennial  Address. 

to  compete  successfully  with  the  best ;  perhaps  we  may  sometime  dedi- 
cate such  a  building  and  department  to  the  name  of  some  honored  public- 
spirited  citizen  of  Worcester. 

Physics,  like  biology,  now  represented  by  a  single  able  and  promising 
man,  needs  enlargement  to  the  same  degree,  with  an  annex  department 
of  astronomy  and  astrophysics,  and  for  the  same  sum  could,  in  addition 
to  what  we  now  have,  be  put  upon  a  creditable  footing. 

The  chemical  building,  admirably  planned  after  careful  studies  of  all 
the  best  in  Europe,  and  well  equipped,  especially  for  organic  work,  has 
no  endowment,  and  needs  for  its  full  development  the  income  of  at  least 
a  quarter  of  a  million  of  dollars. 

Anthropology,  so  greatly  needed  in  this  land,  but  so  lacking  in 
academic  installation  and  tradition  here,  is  already  a  precious  germ  with 
one  worthy  representative,  has  been  cherished  from  the  first  with  us, 
and  it,  too,  needs  enlargement  and  independence. 

If  we  pass  over  into  the  humanities,  there  are,  of  course,  the  two 
great  groups  of  philology  and  literature,  ancient  and  modern,  and  a 
historical  group  culminating  in  political  economy,  sociology,  and  a  grand 
department  of  international  law,  nowhere  adequately  represented  in  this 
country,  and  for  the  establishment  of  which  somewhere  Senator  Hoar, 
acting  president  of  the  Board  of  Trustees,  the  first  citizen  of  Massachu- 
setts, competent  to-day  to  fill  any  one  of  four  professional  chairs  in  any 
university,  in  learning,  experience,  character,  and  position  more  nearly 
the  American  Gladstone  than  any  other,  has  been  so  distinguished  an 
advocate. 

Education,  now  coming  to  be  the  largest  philosophy  of  life  and  the 
natural  field  of  applied  psychology,  needs  a  more  adequate  representa- 
tion, and  with  a  quarter  of  a  million  of  dollars  for  an  ideal  university 
school  for  children,  we  would  almost  guarantee  in  five  years  to  make 
this  place  an  educational  Mecca,  by  short  circuit  methods  now  well 
demonstrated  but  nowhere  embodied,  which  would  greatly  increase  the 
efficacy  and  reduce  the  expense  and  ease  the  labor  of  the  lower  grades 
of  education  in  this  country. 

Our  summer  school  has  become  one  of  the  largest  and  highest 
grade  institutions  of  its  kind  in  the  country,  and  appeals  especially  to 
heads  of  fitting  schools,  with  whom  it  would  be  important  for  us  to  be 
en  rapport  if  we  had  a  college  ;  to  normal  schools,  whose  faculties  are 
a  growing  field  for  the  employment  of  our  pedagogical  graduates  ;    to 


Decennial  Address.  59 

young  instructors  in  colleges,  superintendents,  parents,  etc.  If  our  two 
weeks  could  become  a  summer  quarter  counting  toward  a  degree,  and 
if  the  summer  school  could  be  adequately  endowed  and  furnished,  with 
the  interest  which  one  department  of  our  work  has  already  enlisted 
among  the  teachers  of  our  country,  the  best  of  whom  could  spend  their 
summer  here  in  work,  this,  too,  could  be  made  an  institution  of  which 
any  city  or  university  might  well  be  proud. 

We  urgently  need  without  delay  the  means  for  establishing  a  univer- 
sity printing  office,  where  we  can  publish  our  journals  at  less  expense  and 
do  our  own  printing ;  and  if  this  should  grow  to  larger  dimensions  and 
develop  a  life  of  its  own,  that,  too,  might  be  welcomed. 

These  needs  are  all  on  the  university  plane,  where  the  beginnings 
already  made  are  precious  beyond  words,  wrought  out  as  they  have  been 
with  so  much  pain  and  labor,  and  the  highest  effort  of  so  many  choice 
spirits.  May  the  day  never  dawn  when  this  in  our  country  most  sorely 
needed  and  prayerfully  cherished  academic  tradition  shall  fade  or  be 
broken.  The  investments  of  wealth  and  effort  already  made  are  too 
great,  and  achievements  already  attained  and  future  promise  too  bright, 
to  permit  this  ever  to  be  an  open  question  here. 

Satisfied,  yes  proud,  as  we  are  to-day  to  submit  to  Worcester,  to  sister 
institutions,  and  the  country,  the  records  of  our  work  when  compared  with 
our  means,  we  have  lived,  and  even  now  live  and  walk,  let  us  confess  it, 
to  a  great  extent  in  faith  and  hope,  looking  confidently  to  a  future  larger 
than  our  past  has  been,  with  steadfast  and  immovable  conviction  that  our 
cause  is  the  very  highest  of  all  the  causes  of  humanity,  but  ready  even 
ourselves,  if  need  be,  to  labor  on  yet  longer  in  the  captivity  of  straitened 
resources,  being  fully  persuaded  that  our  redeemer  liveth  and  that  in  due 
time  he  shall  appear. 


THE   DEPAETMENT   OF   MATHEMATICS. 

By  William  Edward  Story. 

PAST   AND  PRESENT   STAFF. 

William  Edward  Story,  Ph.D.,  Professor  of  Mathematics  since  1889. 

OsKAR  BoLZA,  Ph.D.,  Associate  in  Mathematics,  1889-92. 

Henry  Taber,  Ph.D.,  Doceut  in  Mathematics,  1889-92;   Assistant  Professor 

of  Mathematics  since  1892. 
Joseph  de  Perott,  Docent  in  Mathematics  since  1890. 
Henry  S.  White,  Ph.D.,  Assistant  in  Mathematics,  1890-92. 

FELLOWS  AND  SCHOLARS. 

Henry  Benner,  Fellow  in  Mathematics,  1889-90. 

L.  P.  Cravens,  Scholar  in  Mathematics,  1889-90. 

EoLLiN  A.  Harris,  Ph.D.,  Fellow  in  Mathematics,  1889-90. 

J.  F.  McCuLLOCH,  Fellow  in  Mathematics,  1889-90. 

William  H.  Metzler,  Fellow  in  Mathematics,  1889-92. 

J.  W.  A.  Young,  Fellow  in  Mathematics,  1889-92. 

Levi  L.  Conant,  Scholar  in  Mathematics,  1890-91. 

Alfred  T.  De  Lury,  Fellow  in  Mathematics,  1890-91. 

James  N.  Hart,  Scholar  in  Mathematics,  1890-91. 

Thomas  F.  Holgate,  Fellow  in  Mathematics,  1890-93. 

John  I.  Hutchinson,  Scholar  in  Mathematics,  1890-91;   Fellow  in  Mathe- 
matics, 1891-92. 

Frank  H.  Loud,  Scholar  in  Mathematics,  1890-91. 

N.  B.  Heller,  Scholar  in  Mathematics,  1891-92. 

LoRRAiN  S.  HuLBURT,  Fcllow  in  Mathematics,  1891-92. 

John  McGowan,  Scholar  in  Mathematics,  1891-92. 

Ernest  B.  Skinner,  Scholar  in  Mathematics,  1891-92. 

L.  Wayland  Dowling,  Scholar  in  Mathematics,  1892-93;  Fellow  in  Mathe- 
matics, 1893-95. 

John  E.  Hill,  Fellow  in  Mathematics,  1892-95. 

Herbert  G.  Keppel,  Scholar  in  Mathematics,   1892-93;   Fellow  in  Mathe- 
matics, 1893-95. 

61 


62  Department  of 

Thomas  F.  Nichols,  Scholar  in  Mathematics,  1892-93 ;  Fellow  in  Mathematics, 
1893-95. 

F.  E.  Stinson,  Scholar  in  Mathematics,  1892-93;  Fellow  in  Mathematics, 
1893-95. 

W.  J.  Waggener,  Scholar  in  Mathematics  and  Physics,  1892-93. 

Warren  G.  Bullard,  Scholar  in  Mathematics,  1893-96. 

Schuyler  C.  Davisson,  Fellow  in  Mathematics,  1895-96. 

Frederick  C.  Ferry,  Fellow  in  Mathematics,  1895-98. 

John  S.  French,  Scholar  in  Mathematics,  1895-96 ;  Fellow  in  Mathematics, 
1896-98. 

E.  W.  Rettger,  Fellow  in  Mathematics,  1895-98. 

fS.  Edward  Ryerson,  Fellow  in  Mathematics,  1895-96.     Died  March  25, 1896. 

Hugh  A.  Snepp,  Scholar  in  Mathematics,  1895-96. 

James  W.  Boyce,  Fellow  in  Mathematics,  1896-99. 

Herbert  0.  Clough,  Scholar  in  Mathematics,  1896-97. 

A.  Harry  Wheeler,  Scholar  in  Mathematics,  1896-99. 

Lindsay  Duncan,  Scholar  in  Mathematics,  1897-99. 

Frederick  H.  Hodge,  Scholar  in  Mathematics,  1897-98 ;  Fellow  in  Mathe- 
matics, 1898-99. 

Halcott  C.  Moreno,  Scholar  in  Mathematics,  1897-98;  Fellow  in  Mathe- 
matics, 1898-. 

Stephen  E.  Slocum,  Scholar  in  Mathematics,  1897-98 ;  Fellow  in  Mathematics, 
1898-. 

John  N.  Van  der  Vries,  Scholar  in  Mathematics,  1897-98 ;  Fellow  in  Mathe- 
matics, 1898-. 

Frank  B.  Williams,  Scholar  in  Mathematics,  1897-98;  Fellow  in  Mathe- 
matics, 1898-. 

Elwin  N.  Lovewell,  Scholar  in  Mathematics,  1898-99. 

Louis  Siff,  Scholar  in  Mathematics,  1898-99. 

Orlando  S.  Stetson,  Scholar  in  Mathematics,  1898-99. 

SPECIAL  STUDENTS. 

George  F.  Metzler,  Ph.D.,  Honorary  Fellow  in  Psychology,  1891-92. 
Calvin  H.  Andrews,  Mathematics  and  Pedagogy,  1894-95. 
Walter  E.  Andrews,  Mathematics  and  Pedagogy,  1894-95. 


Whole  number  of  students  in  mathematics  in  10  years 44 

Aggregate  attendance  (including  4  who  remain  in  1899-1900)  ...  83  years. 

Average  number  of  students  per  year 8 

Average  attendance  per  student 2  years. 


Mathematics.  63 

Mathematics  occupies  a  peculiar  position  relatively  to  the  arts  and 
sciences.  It  is,  par  excellence,  an  art,  inasmuch  as  its  chief  function 
is  to  solve  problems,  —  not  such  examples  as  are  given  in  the  text-books, 
and  which  serve  only  as  exercises  in  the  application  of  methods,  but  any 
problems  that  may  arise  in  human  experience  and  for  whose  correct  solu- 
tion sufficient  data  are  at  hand.  When  any  line  of  investigation,  to 
whatever  subject  it  may  refer,  has  been  carried  so  far  that  exact  reason- 
ing may  be  applied  to  it,  mathematics  is  the  authority  to  which  the 
results  of  observation  are  submitted  for  the  final  determination  of  their 
consistency  and  the  conclusions  that  may  be  drawn  from  them,  and  fur- 
nishes the  means  of  applying  these  conclusions  to  the  prediction  of  phe- 
nomena not  yet  observed.  No  science  and  no  branch  of  technology  is 
exact,  that  is,  capable  of  predicting  with  certainty  what  will  happen 
under  given  conditions,  unless  it  rests  upon  a  mathematical  foundation. 
Astronomy,  physics,  and  applied  mechanics  already  have  this  foundation 
to  a  considerable  extent,  while  the  other  sciences  are  still  in  the  inductive 
stage,  in  which  material  is  being  collected  with  which,  it  is  to  be  hoped, 
such  foundation  will  ultimately  be  laid.  Mathematics  is  also  a  science, 
inasmuch  as  it  has  accumulated  a  large  body  of  systematic  knowledge 
involving  and  leading  to  the  methods  that  it  employs  in  its  solutions. 
These  methods  are  of  such  a  peculiar  nature,  differing  so  widely  from 
other  methods,  that  a  special  course  of  training  is  requisite  if  any  one 
would  learn  to  use  them,  and  their  number  and  variety  have  become  so 
great  that  a  lifetime  would  not  suffice  to  acquire  familiarity  with  them 
all.  But  new  problems  are  continually  arising  and  demanding  new 
methods,  and  we  need,  therefore,  a  body  of  men  who  shall  devote  them- 
selves especially  to  the  task  of  supplying  this  demand.  While  the  col- 
leges are  engaged  in  general  liberal  education,  teaching  a  variety  of 
subjects  that  develop  the  mental  faculties  (and  no  subject  is  more  effi- 
cient than  mathematics  for  this  purpose)  and  make  the  student  acquainted 
with  his  own  tastes  and  powers,  thus  enabling  him  to  determine  the  life- 
work  for  which  he  is  best  fitted,  it  is  the  special  function  of  the  university 
to  extend  the  limits  of  human  knowledge,  and  to  train  those  who  have 
unusual  intellectual  talents  to  employ  them  to  the  best  advantage.  We 
believe  this  object  is  best  accomplished  by  an  institution  devoted  solely 
to  it,  and  whose  teachers'  energies  are  not  diverted  by  the  lower,  though 
no  less  important,  aims  of  the  college. 

When  the  policy  that  should  characterize  this  University  was  under 


64  Department  of 

discussion,  the  first  point  decided  was  that  its  work  should  be  strictly- 
post-graduate,  and  that  it  should  not  compete  with  other  institutions 
in  the  work  that  is  generally  recognized  as  undergraduate.  In  accordance 
.  with  this  principle,  the  mathematical  department  fixed  its  standard  of 
admission  so  as  to  require  such  a  knowledge  of  mathematics  as  can  be 
obtained  in  the  average  American  college,  and  laid  out  upon  this  foun- 
dation a  curriculum  of  its  own,  as  extensive  and  as  thorough  as  circum- 
stances allowed.  In  elaborating  the  details  of  this  curriculum,  we  have 
kept  in  mind  the  fact  that  those  who  pursue  post-graduate  studies  in 
pure  mathematics  almost  always  look  forward  to  careers  as  professors 
in  colleges  or  other  higher  institutions  of  learning  ;  and  we  have  taken 
the  view  that,  other  things  being  equal,  the  ideal  teacher  is  a  master 
of  his  subject,  not  only  conversant  with  the  general  principles  of  all  its 
more  important  branches,  the  problems  that  have  arisen  in  each,  the 
methods  that  have  been  devised  for  the  solution  of  these  problems,  and 
the  results  that  have  been  obtained,  but  also  unbiassed,  ready  and  sound 
in  judgment,  and  actively  engaged  in  scientific  research.  We  believe 
that  the  training  that  is  best  adapted  to  produce  efficient  specialists  is 
also  the  training  that  is  best  adapted  to  produce  efficient  teachers  of 
specialties. 

While  desirous  of  supplying  all  possible  facilities  to  those  who  wish  to 
pursue  studies  in  special  branches,  and  to  those  who,  already  occupying 
permanent  positions,  have  but  a  limited  leave  of  absence,  we  have  made 
it  our  chief  object  to  provide  a  thorough  training  for  those  who,  having 
just  completed  a  college  course,  have  not  yet  entered  upon  their  life-work. 
This  provision  consists  of  such  courses  of  lectures,  seminaries,  and  indi- 
vidual assistance  as  should  enable  a  faithful  student  endowed  with  the 
proper  natural  ability  to  satisfy  the  requirements  for  the  degree  of  Doctor 
of  Philosophy  at  the  end  of  his  third  year  with  us.  The  requirements 
for  this  degree  have  been  determined  by  our  conception  of  the  ideal 
teacher,  as  already  stated.  To  acquire  the  necessary  breadth  of  knowl- 
edge of  mathematics  as  a  whole,  the  candidate  is  expected  to  attend, 
during  his  first  two  years,  specified  courses  of  lectures  on  the  general 
principles,  methods,  and  results  of  all  the  more  important  branches  of 
pure  mathematics,  to  supplement  these  lectures  by  private  reading,  and  to 
take  an  active  part  in  the  seminary.  In  the  seminary,  a  special  topic, 
more  or  less  directly  connected  with  the  subject  of  some  lecture,  is  as- 
signed, from  time  to  time,  to  each  student,  who  is  required  to  read  it  up 


Mathematics.  65 

and  make  an  oral  report  upon  it  before  the  class.  Advanced  courses  of 
lectures  on  special  subjects  that  vary  from  year  to  year  are  also  given, 
and  each  candidate  for  the  degree  is  expected  to  attend  a  number  of  such 
courses.  The  student  spends  the  greater  part  of  his  third  year  in  the 
original  investigation,  under  the  constant  personal  guidance  of  one  of  the 
instructors,  of  a  topic  of  his  own  selection.  In  preparing  for  this  inves- 
tigation, he  is  required  to  make  a  practically  complete  bibliography  of  the 
subject,  and  to  read  all  the  more  important  available  articles  that  have 
been  written  on  it.  The  results  of  the  investigation,  embodied  in  a  dis- 
sertation suitable  for  printing,  must  be  submitted  to  the  instructor  under 
whose  direction  the  work  was  done,  and  must  receive  his  approval  before 
the  candidate  will  be  admitted  to  the  final  examination  for  the  degree. 
This  approval  will  not  be  given  unless  the  dissertation  is  satisfactory  in 
form  and  completeness  and  the  results  are  sufficiently  novel  and  impor- 
tant to  constitute  a  real  contribution  to  science.  The  dissertation  is,  in 
fact,  the  main  criterion  by  which  the  candidate  is  judged,  and  no  amount 
of  other  work  will  compensate  for  its  defects.  The  ability  of  our  grad- 
uates to  carry  on  research  and  the  excellence  of  the  work  actually  done 
is  assured  by  the  regulation  that  each  dissertation  accepted  by  us  as 
worthy  of  the  degree  shall  be  printed  with  the  explicit  approval  of  a 
member  of  our  Faculty.  It  is  evident  that,  whereas  any  one  that  has  the 
necessary  preparation  and  taste  for  mathematics  may  profit  by  the  advan- 
tages here  afforded,  only  those  who  have  a  certain  amount  of  mathematical 
genius  can  secure  the  degree. 

In  making  appointments  to  fellowships  and  scholarships  we  have 
endeavored  to  maintain  the  same  high  standard.  We  are  on  the  lookout 
for  mathematical  geniuses  ;  but  it  is  difficult  to  determine  from  the  evi- 
dence of  others  whether  candidates  come  up  to  our  standard  or  not ;  so 
that  we  have  adopted  the  general  policy  of  giving  the  best  appointments 
to  those  only  that  have  been  with  us  for  at  least  one  year,  and  about 
whom  we  are  in  position  to  judge  for  ourselves.  Of  course,  this  policy 
could  not  be  carried  out  during  the  earlier  years  of  the  University,  and 
its  effect  is  apparent  in  the  fact  that,  whereas  seventy-five  per  cent  of  the 
students  that  entered  the  mathematical  department  during  the  first  three 
years  remained  with  us  but  one  year,  only  twenty  per  cent  of  those  that 
have  been  admitted  during  the  last  seven  years  left  at  the  end  of  their 
first  year.  I  do  not  mean  to  imply  that  those  who  left  before  completing 
our  course  were  inferior  in  ability  to  those  who  remained  three  years,  but 


66  Department  of 

we  desire  particularly  to  encourage  men  who  can  and  will  go  forward  to 
the  degree. 

Nearly  all  of  those  who  have  studied  mathematics  with  us  have 
adopted  teaching  as  a  profession,  two-thirds  are  now  members  of  college 
faculties,  and  one-third  are  engaged  in  higher  school  work.  Those  who 
have  received  the  doctor's  degree  have  generally  secured  at  once  desir- 
able positions  in  which  to  begin  their  life-work,  and  most  of  them  have 
already  acquired  for  themselves,  by  distinguished  ability,  very  decided 
influence  in  the  institutions  with  which  they  are  connected.  Of  those 
who  have  left  without  the  degree  fully  one-half  ought  to  have  continued, 
and  would  have  done  so  but  for  want  of  pecuniary  means ;  and  we  have 
been  obliged  to  turn  away  many  men  of  very  great  promise  on  account  of 
our  inability  to  assist  them  in  providing  the  means  of  subsistence  during 
the  unproductive  period  of  student  life.  We  could  employ  for  fellow- 
ships, with  decided  advantage,  ten  times  the  amount  now  at  our  disposal. 

Although,  as  I  believe,  students  will  find  here  a  broader  post-graduate 
curriculum  in  mathematics  and  greater  personal  attention  from  the  in- 
structors than  at  any  other  university  in  the  country,  we  need  greater 
facilities  to  make  our  course  what  it  ought  to  be.  Four-fifths  of  the  in- 
struction in  the  department  is  now  given  by  two  men,  and  we  are  com- 
pelled to  give  in  alternate  years  lectures  on  fundamental  subjects  that 
ought  to  be  given  every  year.  As  I  have  said,  we  lay  great  stress  upon 
the  ability  of  our  students  to  investigate ;  but  this  faculty  can  be  fully 
developed  only  under  the  personal  guidance  of  one  who  is  himself  in  the 
habit  of  investigating  and  who  has  the  facilities  and  opportunities  neces- 
sary for  such  work.  A  teacher's  usefulness  is  greatly  increased  b}^  the 
inspiration  that  comes  from  a  personal  identification  with  his  subject, 
from  the  fact  that  he  has  ideas  of  his  own  about  it,  and  that  he  has  ex- 
tended it  by  his  individual  exertions ;  and  tlie  investigator  can  have  no 
greater  incentive  to  search  for  new  results  than  the  opportunity  to  pre- 
sent his  thoughts  and  discoveries  to  an  intelligent  and  appreciative  class 
in  the  lecture-room.  But  the  necessity  of  teaching  many  subjects  simul- 
taneously distracts  the  mind  and  is  fatal  to  research.  The  ideal  condi- 
tions for  an  instructor  in  an  institution  like  this  would  be  those  under 
which  he  could  teach  one  subject  at  a  time,  and  that  a  subject  that  he 
was  himself  developing,  and  follow  this  subject  with  his  class  to  such 
a  point  as  to  bring  into  evidence  the  scope  and  importance  of  his  own 
work.     To  apply  this  method  to  the  courses  that  are  actually  given  here 


Mathematics.  67 

would  require  the  services  of  three  additional  instructors  in  mathematics. 
We  are  actually  laboring  under  the  disadvantage  that  some  of  the  im- 
portant branches  now  taught  by  us  are  not  of  such  paramount  interest 
to  any  one  of  our  instructors  as  to  be  the  subject  of  his  personal  investi- 
gation. We  are  compelled  to  restrict  ourselves  to  elementary  courses  in 
many  branches  that  ought  to  be  carried  to  a  much  higher  point,  and  to 
omit  altogether  from  our  consideration  applications  of  mathematics  to 
statistics,  to  the  arts,  and  to  other  sciences.  Applications  to  physics  re- 
ceive the  attention  of  the  physical  department,  to  be  sure,  but  the  mathe- 
matical department  ought  to  do  much  more  than  it  is  at  present  able  to 
do  in  preparing  students  for  higher  work  in  physics.  The  number  of 
instructors  necessary  for  such  advanced  work  as  we  do  is  not  to  be  deter- 
mined by  the  number  of  our  students,  but  by  the  number  of  subjects 
taught. 

Again,  every  expert  investigator  finds  himself  continually  obliged  to 
spend  much  time  in  details  that  could  just  as  well  be  worked  out  by  a 
younger  man,  to  whom  such  work  would  be  of  immense  advantage,  not 
only  as  an  exercise  in  the  practical  application  of  methods,  but  also  as 
furnishing  the  opportunity  for  a  prolonged  study  of  the  workings  of  an 
investigator's  mind ;  and  example  is  worth  more  than  precept  in  the 
development  of  the  faculty  of  investigation.  We  ought  to  have  the 
means  of  retaining  our  best  graduates  for  a  year  or  two  as  personal  assist- 
ants to  the  instructors,  during  which  period  they  might  also  be  gaining 
experience  in  the  class-room  by  teaching  a  few  hours  a  week  under  the 
supervision  of  one  of  the  regular  instructors.  Such  work  is  not  drudgery, 
and  would  be,  I  think,  sufficiently  attractive  to  an  ambitious  young  man 
to  induce  him  to  remain  with  us  on  a  moderate  stipend  while  he  is  wait- 
ing for  such  appointment  as  may  seem  to  him  desirable. 

It  is  almost  universally  assumed  that  a  mathematician  needs  no  mate- 
rial equipment  other  than  brains,  with,  possibly,  a  few  books.  However 
true  this  assumption  may  have  been  some  decades  ago,  —  and  I  fancy  that 
its  truth  then  rested  solely  upon  the  difficulty  of  procuring  such  equi]3- 
ment,  —  it  is  not  true  now,  as  must  be  apparent  to  any  one  who  studied 
carefully  the  German  educational  exhibit  at  the  World's  Fair  in  Chicago. 
Ten  years  ago  our  department  started  out  with  a  fair  nucleus  for  a 
mathematical  library  and  a  moderate  collection  of  models,  to  which  we 
have  not  been  able  to  make  many  additions.  We  have  very  few  of  the 
older  mathematical  works  that  illustrate  the  history  of  the  subject,  and 


68  Department  of 

we  need  particularly  complete  sets  of  many  important  mathematical  jour- 
nals and  the  transactions  of  learned  societies.  In  these  journals  and 
transactions  have  appeared  most  of  the  original  investigations  to  which, 
as  investigators  ourselves,  we  have  continual  occasion  to  refer,  both  for 
suggestions  and  to  avoid  apparent  plagiarism  and  the  unnecessary  dupli- 
cation of  research.  We  should  also  be  greatly  assisted  in  our  class-work 
by  a  more  complete  collection  of  models. 

In  short,  what  I  have  in  mind  as  a  model  mathematical  department 
for  post-graduate  work  would  have,  say,  four  professors  and  assistant 
professors,  each  having  his  personal  assistant,  and  at  least  two  instructors 
of  lower  grade  for  the  more  elementary  work,  and  would  be  provided 
with  a  complete  mathematical  library  and  -with  all  the  apparatus  that  it 
is  now  possible  to  prociu'e,  with  suitable  provision  for  tlie  purchase  of 
new  books  and  apparatus  as  they  appear  in  the  market. 

These  schemes  are  not  incapable  of  realization,  although,  perhaps, 
opposed  to  the  traditions  of  education  in  this  country.  This  University 
has  never  had  any  traditions  excepting  such  as  were  based  upon  high 
ideals.  Its  mathematical  department  was  not  modelled  after  that  of  any 
other  institution,  but  was  determined  by  the  conception  of  what  would 
constitute  perfection  in  such  a  department.  We  have  always  lived  up  to 
our  ideals,  in  so  far  as  Ave  have  done  anything,  without  regard  to  consid- 
erations of  material  interest.  We  are  not  here  to  do  what  is  done  else- 
where, and  we  do  not  acknowledge  that  it  Avould  be  best  for  us  to  do  what 
other  institutions,  in  their  experience,  have  thought  wisest.  We  propose 
to  adopt  no  temporary  policy  that  we  shall  sometime  want  to  abandon, 
confident  that  the  ideal  university  of  the  future  will  be  ideal  from  the 
very  root  and  not  a  graft  upon  inferior  stock. 

When  the  doors  of  the  Universty  were  first  opened  to  students,  in  the 
fall  of  1889,  the  mathematical  staff  consisted  of  William  E.  Stor}-,  Pro- 
fessor, Oskar  Bolza,  Associate,  and  Henry  Taber,  Decent ;  a  year  later  it 
was  increased  by  the  appointment  of  Joseph  de  Perott,  Doceut,  and 
Henry  S.  Wliite,  Assistant ;  and  in  1892  Drs.  Bolza  and  White  resigned 
their  positions  to  accept  Associate  Professorships  in  the  University  of 
Chicago  and  Northwestern  Universit}^,  respectively,  and  Dr.  Taber  was 
promoted  to  an  Assistant  Professorship,  thus  leaving  the  department  with 
practically  the  same  teaching  force  as  it  had  during  the  first  year. 

The  instruction  has  been  given  by  lectures,  seminaries,  and  individual 
conferences.     The  number  of  lectures  (of  fifty  minutes  each)  was  sixteen 


Mathematics.  69 

a  week  the  first  year,  nineteen  and  twenty  a  week  in  the  second  and 
third  years,  respectively,  and  about  fourteen  a  week,  on  the  average,  each 
year  since.  In  some  years  courses  of  lectures  on  certain  mathematical 
subjects  having  important  physical  applications  have  been  given  by 
Assistant  Professor  Webster  of  the  Department  of  Physics. 

The  subjects  of  the  lecture  courses  given  during  the  ten  years  include 
the  following  :  — 

1.  The  History  of  Arithmetic  and  Algebra  among  various  peoples  from  the 
earliest  times  to  1650  a.d. 

2.  Theory  of  Numbers  (introductory). 

3.  Theory  of  Numbers  (advanced). 

4.  Numerical  Computations. 

6.  Theory  of  Quadratic  Forms. 

6.  Finite  Differences. 

7.  Probabilities. 

8.  Theory  of  Errors  and  the  Method  of  Least  Squares. 

9.  Theory  of  Functions  of  a  Real  Variable. 

10.  Linear  Transformations  and  Algebraic  Invariants  (introductory). 

11.  Theory  of  Substitutions,  with  applications  to  algebraic  equations  (intro- 
ductory). 

12.  Theory  of  Transformation  Groups. 

13.  The  Application  of  Transformation  Groups  to  Differential  Equations. 

14.  Finite  Continuous  Groups. 

15.  Klein's  Icosahedron  Theory. 

16.  Simultaneous  Equations,  including  Eestricted  Systems. 

17.  Theory  of  Functions  of  a  Complex  Variable,  according  to  Cauchy,  Rie- 
mann,  and  Weierstrass  (introductory). 

18.  Definite  Integrals  and  Fourier's  Series  (introductory). 

19.  Ordinary  Differential  Equations  (introductory). 

20.  Ordinary  Differential  Equations  (advanced). 

21.  Partial  Differential  Equations  (introductory). 

22.  Elliptic  Functions,  according  to  Legendre  and  Jacobi  (introductory). 

23.  Weierstrass's  Theory  of  Elliptic  Functions. 

24.  Elliptic  Modular  Functions. 

25.  Abelian  Functions  and  Integrals. 

2,6.  Theta-Functions  of  Three  and  Four  Variables. 

27.  Riemann's  Theory  of  Hyperelliptic  Integrals. 

28.  Riemann's  Surfaces  and  Abelian  Integrals. 

29.  Conic  Sections  by  modern  analytic  methods  (introductory). 

30.  Quadric  Surfaces  by  modern  analytic  methods  (introductory). 

31.  General  Theory  of  Higher  Plane  Curves  (introductory). 

32.  Plane  Curves  of  the  Third  and  Fourth  Orders. 


70  Department  of 

33.  General  Theory  of  Surfaces  and  Twisted  Curves  (introductory). 

34.  Surfaces  of  the  Third  and  Fourth  Orders. 

35.  Twisted  Curves  and  Developable  Surfaces  (advanced). 

36.  Applications  of  the  Infinitesimal  Calculus  to  the  Theory  of  Surfaces. 

37.  Rational  and  Uniform  Transformations  of  Curves  and  Surfaces. 

38.  Enumerative  Geometry. 

39.  Analysis  Situs. 

40.  Hyperspace  and  Non-Euclidean  Geometry. 

41.  Modern  Synthetic  Geometry  (introductory), 

42.  Quaternions,  with  applications  to  geometry  and  mechanics. 

43.  Multiple  Algebra,  including  matrices,  quaternions,  "  Ausdehnungslehre," 
and  extensive  algebra  in  general. 

44.  Symbolic  Logic. 

Courses  designated  as  "  introductory  "  are  given  at  least  as  often  as 
every  other  year,  and  attendance  on  tliem  is  required  of  all  candidates 
for  the  degree  of  Doctor  of  Philosophy  that  take  mathematics  as  their 
principal  subject.  The  other  courses,  intended  primarily  for  the  more 
advanced  students,  have  been  given  less  frequently  and  vs^ith  particular 
reference  to  the  suggestion  of  topics  for  original  investigation. 

In  connection  with  his  lectures,  Assistant  Professor  Taber  has  con- 
ducted a  weekly  seminary  for  students  in  their  first  or  second  year,  for 
the  purpose  of  cultivating  in  them  an  active  attitude  toward  the  subjects 
treated,  instead  of  the  passive  attitude  usually  resulting  from  hearing 
lectures.  Topics  related  to  those  of  the  lectures  have  been  discussed 
by  the  students,  and  their  work  has  been  criticised  both  with  reference 
to  rigor  of  demonstration  and  manner  of  presentation.  In  this  way  some 
of  the  advantages  of  the  laboratory  and  the  practice  school  are  brought 
into  the  field  of  mathematics.  Professor  Story,  with  the  assistance  of 
the  other  instructors,  has  directed  the  more  advanced  students  individ- 
ually in  the  systematic  investigation  of  special  topics  that  promised  to 
afford  opportunity  for  the  discovery  of  new  results  and  methods,  —  a  task 
that  has  sometimes  required  the  professor  to  hold  weekly  three-hour 
conferences  with  each  of  four  students  during  nearly  the  entire  academic 
year  ;  but  we  believe  the  results  have  justified  this  unusual  expenditure 
of  energy. 

The  average  annual  number  of  students  taking  mathematics  as  their 
chief  study  has  been  about  eight,  the  average  duration  of  their  residence 
was  about  two  years,  and  more  than  one-third  of  them  have  received  (or  will 
undoubtedly  receive)  the  Doctor's  degree,  which  is  a  decided  improve- 


Mathematics.  71 

ment  in  every  respect  over  the  record  of  the  first  three  years.  The  pub- 
lished investigations  of  these  students  are  enumerated  in  the  Bibliography 
at  the  end  of  this  volume. 


The  researches  of  an  instructor  in  an  institution  of  this  kind  are  not 
to  be  judged  solely  by  the  number  and  magnitude  of  his  printed  papers, 
as  many  of  them  are  naturally  turned  over,  in  a  more  or  less  incom- 
plete form,  to  his  pupils  for  further  investigation  and  more  adequate 
presentation  ;  at  least  it  seems  most  natural  and  desirable  that  an  in- 
structor should  suggest  to  his  pupils  subjects  for  investigation  on  which 
he  has  himself  worked,  and  for  whose  treatment  he  has  found  adequate 
methods. 

My  chief  subjects  of  investigation  have  been  :  — 

1.  Hyperspace  and  Non-Euclidean  Geometry. 

2.  Algebraic  Invariants. 

3.  Curves  on  Ruled  Surfaces,  and  Restricted  Equations. 

4.  The  History  of  Mathematics  prior  to  the  invention  of  the  infinitesimal 
calculus,  and 

5.  A  Mathematical  Curriculum  for  Primary  and  Secondary  Schools. 

I  have  developed  systematically  the  general  theory  of  space  of  any 
number  of  dimensions  from  assumptions  that  are  precisely  analogous  to 
those  on  which  the  scientific  treatment  of  threefold  space  is  usually  based, 
and  which  we  recognize  as  the  results  of  experience.  In  accordance  with 
this  general  theory,  I  have  thoroughly  investigated  the  properties  of  loci 
of  the  first  and  second  orders  and  some  special  loci  of  higher  orders. 
The  introduction  of  the  most  general  kind  of  measurement  has  then  led 
me  to  an  equally  thorough  study  of  parallel  and  perpendicular  loci,  the 
curvature  of  loci,  areas,  and  volumes  in  the  most  extended  sense.  The 
first  part  of  these  results  has  already  appeared  in  the  Mathematical 
Review^  and  I  hope  to  publish  the  remainder  within  a  short  time. 

Ever  since  the  appearance  of  Clebsch's  "  Theorie  der  binaeren  alge- 
braischen  Formen,"  toward  the  end  of  the  year  1871,  when  I  was  study- 
ing in  Berlin,  I  have  taken  a  lively  interest  in  the  theory  of  algebraic 
invariants,  —  an  interest  that  was  greatly  augmented  by  my  association 
with  Sylvester  at  the  Johns  Hopkins  University  in  1876.  I  had  thought 
all  along  that  there  ought  to  be  a  direct  process  by  which  all  such  inva- 


72  Department  of 

riants  could  be  obtained,  but  my  efforts  to  find  it  had  failed.  A  course 
of  lectures  on  invariants  that  I  have  given  every  year  or  two  since  the 
opening  of  Clark  University  caused  me  to  renew  my  attempts,  and  the 
classic  paper  of  Hilbert  in  the  36th  volume  of  the  Mathematische 
Annalen,  in  which  a  process  devised  by  Mertens  (and  which  I  regarded 
as  indirect,  inasmuch  as  it  involved  quantities  extraneous  to  the  matter 
in  question)  suggested  a  new  line  of  research,  which  happily  led  at  length 
to  the  long-sought  direct  process.  I  then  applied  this  process,  as  Hilbert 
had  applied  Mertens's  process,  to  the  proof  of  Gordon's  theorem  that  all 
the  invariants  of  any  finite  system  of  quantics  of  finite  orders  can  be 
expressed  rationally  in  terms  of  a  finite  number  of  such  invariants. 
These  results  were  published  in  the  Mathematische  Annalen  and  in  the 
Proceedings  of  the  London  Mathematical  Society.  I  have  spent  much  time 
in  trying  to  find,  by  means  of  the  process,  an  extension  of  Cayley's  for- 
mula for  the  number  of  linearly  independent  ground-forms  of  a  single 
binary  quantic  (extended  by  Sylvester  to  any  system  of  binary  quantics) 
to  the  case  of  quantics  involving  three  or  more  variables,  but  so  far  with- 
out success. 

In  my  lectures  on  surfaces  of  higher  orders  and  twisted  curves  I  have 
paid  particular  attention  to  the  algebraic  curves  that  lie  upon  a  given 
algebraic  surface.  If  the  given  surface  is  ruled,  the  curves  on  it  can  be 
classified  in  such  a  way  that  certain  problems  relating  to  a  curve  can  be 
solved  when  the  class  of  the  curve  is  known.  My  investigations  in  this 
direction  have  been  communicated  to  my  students,  some  of  whom  have 
already  solved  such  problems.  In  connection  with  my  investigations  on 
twisted  curves,  I  have  also  made  a  systematic  study  of  restricted  equa- 
tions, and  have  carried  the  determination  of  the  orders  of  such  systems 
much  farther  than  had  been  done  before. 

I  have  lectured  at  various  times  on  the  early  history  of  mathematics, 
with  special  reference  to  the  development  of  arithmetical  and  algebraic 
symbolism,  and  have  collected  a  large  number  of  systems  of  such  symbols, 
which  I  hope  sometime  to  utilize  for  a  monograph  on  the  subject. 

In  connection  with  a  course  of  lectures  delivered  for  two  years  at  the 
Summer  School,  I  arranged  a  mathematical  curriculum  for  primary  and 
secondary  schools,  which  will  be  published  when  I  can  find  the  leisure 
necessary  to  prepare  the  explanatory  text. 

At  my  request.  Assistant  Professor  Taber  has  furnished  the  material 
for  an  account  of  his  personal  researches,  which  involves  such  a  complete 


Mathematics.  73 

and  excellent  history  of  the  theory  of  matrices  that  it  seems  to  me  inad- 
visable to  abbreviate  it ;  I  therefore  append  it  to  this  report  at  length,  for 
the  benefit  of  those  readers  who  may  be  interested  in  the  subject. 


Dr.  Taber's  researches  have  been  devoted  to  the  development  of  the 
theory  of  matrices,  and  its  application  to  bilinear  forms,  multiple  algebra, 
and  theory  of  finite  continuous  groups.  The  calculus  or  theory  of  matrices 
was  invented  by  Professor  Cayley  (see  his  "  Memoir  on  the  Theory  of 
Matrices,"  Phil.  Trans..,  1858),  and  has  proved  an  instrument  of  great 
power  in  the  theory  of  linear  transformation,  bilinear  forms,  and  for  the 
investigation,  generally,  of  the  projective  group. i  In  order  to  explain 
the  work  done  by  Dr.  Taber  in  this  direction,  a  few  words  of  explanation 
will  be  necessary  to  describe  the  work  done  by  Cayley  and  others. 

Associated  with  any  linear  substitution 


n 

c/  =S\<^ijXj  (i  =  1,  2,  •••  w) 


is  the  bilinear  form  -^  =  /    /    ('(■ij^iVj-i  which  may  be  regarded  as  repre- 

senting  this  substitution,  or  vice  versa  ;  and,  in  the  theory  of  matrices,  we 
do  not  need  to  distinguish  between  this  linear  substitution  and  the  asso- 
ciated bilinear  form,  or  between  either  and  the  matrix  (  .    ,        '^" 

\i,j  =  1,  2,  ...w 

n         rt 

common  to  both.     If  now  B  denotes  the  bilinear  form  y    \    ^ya^t^^?  or 

1      1   ^ 
its   associated  linear   substitution,  A±B  will  denote  the  bilinear  form 

n         n 

y^  y^  (ajj  +  hjj)Xii/p  or  its  associated  linear  transformation ;  and  AB 
will   denote   the   bilinear   form    /  ^y  ^\/  ^  cLii^ki]^%y}->  oi'  its  associated 

linear  substitution  (obtained  by  the  composition  of  the  linear  substitutions 
A  and  B).     Equivalence  between  two  bilinear  forms  or  linear  substitu- 

1  By  means  of  this  calculus  very  important  results  have  been  obtained  by  Cayley  himself, 
by  Sylvester,  Frobenius,  Toss,  Weyer,  Study,  and  others ;  and,  by  methods  essentially  simi- 
lar, Kronecker  obtained  important  theorems  on  the  orthogonal  group  to  which  reference  is 
made  below. 


74  Department  of 

tions,  A  and  B,  is  denoted  by  writing  A  =  B.  Further,  in  what  follows, 
I  will  denote  the  identical  transformation,  represented  by  2^.a^.yo  and 
A-^   the  form,  or  substitution,  satisfying   the  symbolic  equation  AA-^ 

n  n 

=  A-^A  =  I;  A  will  denote  the  bilinear   form V"  >^  aj,a:,y,,  transverse 

or  conjugate  to  A  =y^  y"  ayX^i/j,  and  \A\  will  denote  the  determinant 

1      1 
of  the  matrix  A.     A  is  said  to  be  symmetric  if  A  =  A,  and  alternate,  or 

skew  symmetric,  if  A=:  —  A.^ 

Cayley  was,  perhaps,  led  to  the  invention  of  this  calculus  by  his 
researches  upon  orthogonal  substitution,  Crelle  (1846),  Vol.  32.  For 
in  Crelle,  Vol.  50,  three  years  before  the  publication  of  his  memoir  on 
matrices,  he  expressed  the  results  of  these  researches  in  the  notation  of 
matrices.  Thus  Cayley  showed  that  the  general  expression  for  the  proper 
orthogonal  substitution  in  n  variables  is  (J—  ^)(7+  -5)-\  where  B 
denotes  an  arbitrary  alternate,  or  skew  symmetric,  linear  substitution ; 
and  this  expression  gives  Cayley's  determination  of  the  coefficients  of  a 
proper  orthogonal  substitution  in  n  variables  as  rational  functions  of  the 
essential  parameters,  |^w(w  — 1)  in  number. 

Again,  in  his  "  Memoir  on  the  Automorphic  Linear  Transformation  of 
a  Bipartite  Quadrate  Function"  {Phil.  Trans.,  1858),  Cayley  showed  that 
the  general  automorphic  linear  transformation  (linear  transformation  into 

n         n 

itself)  of  a  symmetric  (alternate)  bilinear  form  A  =  y    \    ^tpiVj  with 

1      1 
cogredient  variables  and  of  non-zero  determinant,  may  be  represented  by 

(A  +  X^~^(A  —  X),  where  X  is  an  arbitrary  alternate  (symmetric)  bi- 
linear form.  This  expression  gives  in  the  first  case  (when  A  is  symmet- 
ric) Hermite's  determination  of  the  general  proper  automorphic  linear 
transformation  of  a  symmetric  bilinear  form,  and,  in  the  second  case 
(when  A  is  alternate),  Cayley's  determination  of  the  transformation  into 
itself  of  an  alternate  bilinear  form.  Further,  in  this  same  memoir  Cay- 
ley showed  how  to  reduce,  to  the  solution  of  a  system  of  n^  linear  equa- 
tions, the  rational  determination  of  the  n^  coefficients  of  the  automorphic 
linear  transformation  of  a  general  bilinear  form  A  (neither  symmetric 
nor  alternate)  with  cogredient  variables  and  of  non-zero  determinant. 
Namely,  he  showed  that  the  general  formula  for  such  a  substitution  is 

i  In  the  first  case  aji  =  ay,  in  the  second  aji  =  —  Oy  (i,  j  =  1,  2,  •••  n). 


Mathematics.  75 

{A  +  X)-\A-X),  where  X satisfies  the  condition  (Jl)-^  X  +  A-^X  =  0. 
This  result  includes  the  determination  of  the  general  automorphic  trans- 
formation of  A^  when  A  is  symmetric  and  when  A  is  alternate.  It  also 
includes  Cayley's  determination  of  the  coefficients  of  an  orthogonal  substi- 
tution to  which  it  reduces  when  A  =  I. 

In  what  follows  Cr  will  denote  the  group  of  proper  automorphic  linear 
transformations  of  A  (the  a;'s  and  ^'s  being  cogredient),  and  Gr'  the  proper 
orthogonal  group.  A  transformation  T  oi  Cr  (or  of  6r')  is  termed  singular 
if  —1  is  a  root  of  its  characteristic  equation  (namely,  ]  T—  pl\  =0); 
otherwise,  non-singular.  Every  non-singular  transformation  of  group  G- 
(or  (^')  is  given  by  Cayley's  formula,  and  may  be  termed  a  Cayleyan 
transformation  of  the  group.  ^  No  singular  transformation  of  group  G  is 
given  by  Cayley's  expression  or  determination.  But  for  A  alternate,  also 
when  A  is  neither  symmetric  nor  alternate  provided  (  J.  ±  J.  |  ^0,  Dr. 
Taber  showed  in  1894  {Proc.  Am.  Acad.  Arts  and  Sciences,  Vol.  29)  that 
group  G  is  generated  by  the  Cayleyan  transformations  of  the  group,  — 
each  transformation  T  of  this  group  being  obtained  by  the  composition  of 
a  finite  number  of  Cayleyan  transformations.  In  the  same  paper  Dr.  Taber 
also  showed  that  the  sub-group  of  orthogonal  transformations  of  G-  is, 
similarly,  generated  by  the  non-singular  orthogonal  transformations  of 
this  sub-group,  when  A  is  alternate,  and  when  A  =^  ±  A  provided 
\A±  A\  =^0. 

This  theorem  is  similar  to  a  theorem  relating  to  the  orthogonal  group 
(group  G'}  established  by  Kronecker  in  1890  ("  Ueber  orthogonale  Sys- 
teme,"  Sitzungsherich.  d.  Freuss.  Akad.},  who  showed  that  this  group 
is  generated  by  the  Cayleyan  transformations  of  the  group,  each  trans- 
formation T  of  this  group  being  obtained  by  the  composition  of  two 
Cayleyan  transformations,  —  the  coefficients  of  each  of  the  Cayleyan 
transformations  being  rational  functions  of  the  coefficients  of  T. 

In  1895  (Math.  Ann.,  Vol.  46)  Dr.  Taber  showed  that,  if  A  is  real  and 
alternate,  every  real  transformation  T  oi  G  can  be  obtained  by  the  com- 
position of  two  real  Cayleyan  transformations  of  this  group.  This 
theorem  was  obtained  independently  and  extended  widely  by  Dr.  Loewy, 
who  in   1896    (^Math.  Ann.,  Vol.  48)  showed   that,   if  A   is   irreducible 

1  For  the  case  in  which  A  is  symmetric,  the  determination  of  the  coefficients  of  T",  given 
by  Cayley's  formula,  is  properly  Hermite's  •,  but  it  is  not  convenient  to  distinguish  here 
between  this  case  and  the  other  two  cases,  namely,  when  A  is  alternate,  or  is  neither 
symmetric  nor  alternate,  when  the  determination  is  Cayley's. 


76  Department  of 

(which  case  includes  that  in  which  A  is  alternate),  every  transformation 
of  Q-^  real  or  imaginary,  can  be  obtained  by  the  composition  of  two 
Cayleyan  transformations  of  the  group,  and  that,  therefore,  when  A  is 
irreducible,  there  is  no  transformation  of  the  kind  termed  by  Foss 
essentially  singular}  that  is  to  say,  which  cannot  be  obtained  by  the  com- 
position of  two  non-singular,  or  Cayleyan,  transformations. 

For  a  reducible  form  A  not  every  singular  transformation  of  G-  can  be 
obtained  by  the  composition  of  two  Cayleyan  transformations  of  this 
group.  Nevertheless,  Dr.  Taber  showed  in  1897  {Math.  Review^  Vol.  1) 
that  in  every  case  the  Cayleyan  transformations  of  Gr  form  a  group  by 
themselves ;  that  the  composition  of  any  number  of  Cayleyan  transforma- 
tions of  Gr  results  in  a  transformation  that  can  be  obtained  by  the 
composition  of  two  Cayleyan  transformations  of  this  group;  and  that  thus 
the  composition  of  Cayleyan  transformations  never  gives  rise  to  an 
essentially  singular  transformation. 

It  is  to  be  noted  that  from  Cayley's  formula  for  a  transformation  T  of 
Cr^  namely, 

T=  iA  -f  Xy  (^  -  X)  =  (J-  ^-iX)(J4-  A-'xy\ 

we  derive  X=A(1  -  T)(l  +  T)-^; 

and,  therefore,  the  parameters,  namely,  the  coefficients  of  X,  which  enter 
into  the  determination  of  T,  can  be  expressed  rationally  in  the  coefficients 
of  T  and  of  A.^  Similarly,  in  the  memoir  by  Kronecker  mentioned  above, 
he  has  shown  that  the  coefficients  of  the  two  Cayleyan  transformations, 
whose  composition  gives  the  general  transformation  T  of  group  Gr',  can  be 
expressed  rationally  in  the  coefficients  of  T.  For  A  real,  alternate,  and 
orthogonal.  Dr.  Taber  gave,  in  the  paper  in  the  Mathematische  Annalen 
mentioned  above,  the  determination  of  the  coefficients  of  the  two  Cayleyan 
transformations  C^  and  O^,  whose  composition  gives  any  real  transforma- 
tion T  of  Gr,  as  rational  functions  of  the  coefficients  of  T  and  of  A.  This 
determination  of  (7j  and  C^  he  has  since  extended  to  the  case  in  which  T 
is  imaginary,  and  A  any  alternate  bilinear  form.^ 

Dr.  Taber  has  pointed  out  that  the  transformations  of  Gr,  both  when 
A  is  irreducible  and  when  A  is  reducible,  are  in  general  of  two  essentially 

1  Abhand.  d.  k.  Bayer.  Akad.  d.  Wiss.,  II.  CI.,  XVII.  Bd.,  II.  Abth.  1890,  p.  77. 

2  Between  these  parameters  ■when  A  is  neither  symmetric  nor  alternate  n^  equations 
persist. 

2  See  papers  to  appear  in  Proc.  Am.  Acad,  of  Arts  and  Sciences,  Vol.  35. 


Mathematics.  77 

different  kinds.    The  difference  between  the  two  kinds  of  transformations 
of  Gr  is  given  by  the  following  theorem :  — 

(I.)  If  we  designate  a  transformation  of  group  G  as  of  the  first  or  sec- 
ond kind  according  as  it  is  or  is  not  the  second  power  of  a  transformation 
of  the  group^  then  every  transformation  of  the  first  kind  is  the  rath  power 
of  a  transformation  of  the  group,  for  any  positive  integer  m,  and  can  he 
generated  hy  the  repetition  of  an  infinitesimal  transformation  of  the  group. 
A  transformation  of  the  second  kind,  hy  definition  not  an  even  power  of  any 
transformation  of  the  group,  is  always  the  (2m  +  l)"*  power  of  a  transforma- 
tion of  the  group  for  any  odd  exponent  2m  +  1.  But  no  transformation  of 
the  second  kind  can  he  generated  hy  an  infinitesimal  transformation  of  the 
group. 

(II.)  Every  Cayleyan  transformation  of  group  G  is  a  transformation 
of  the  first  kind  ;  whereas,  a  non-  Cayleyan  transformation  is,  in  general,  of 
the  second  kind.^ 

Dr.  Taber  has  also  given  the  conditions  necessary  and  sufficient  that 
a  transformation  T  of  group  Gr  may  be  of  the  first  kind  for  the  case  in 
which  A  is  symmetric  (which  includes  the  case  when  ^  =  /,  in  which  case 
G  becomes  Gr'),  and  for  the  case  when  A  is  alternate. ^ 

Dr.  Taber  has  shown  that,  if  A  is  neither  symmetric  nor  alternate  and 

1  This  was  proved  for  the  orthogonal  group  in  1894,  Bull.  Am.  Math.  Sac,  Vol.  3.  At 
the  conclusion  of  this  paper  it  was  stated  that  a  precisely  similar  theorem  held  for  what 
is  here  designated  as  group  G.  In  the  Math.  A7171.,  1895,  "Vol.  46,  the  theorem  was  proved 
for  group  Gf  when  A  is  alternate;  for  the  case  in  which  A  is  symmetric,  in  the  Proc. 
Lond.  Math.  Soc,  1895,  Vol.  26;  and  for  the  general  case,  in  the  Math.  Beview,  1897, 
Vol.  1. 

2  For  the  orthogonal  group,  to  which  G  reduces  when  A  =  I,  the  conditions  necessary  and 
sufficient  that  a  transformation  shall  be  of  the  first  kind  were  given  by  Dr.  Taber  in  a  com- 
munication to  the  American  Academy  of  Arts  and  Sciences,  March,  1895.  (See  Proceedings, 
Vol.  30,  p.  551.)  The  necessity  and  sufficiency  of  these  conditions  was  afterwards  shown  in 
Proc.  Lond.  Math.  Soc,  1895,  Vol.  26,  and  the  theory  for  the  orthogonal  group  extended 
to  group  G  for  A  symmetric.  It  was  not  explicitly  stated  in  this  paper  that  the  conditions 
given  for  the  orthogonal  group  hold  for  G  when  A  is  symmetric,  being  so  obvious  a  conse- 
quence of  the  considerations  adduced.  This  does  not  seem  to  have  been  recognized  by  Dr. 
Loewy,  who  refers  to  this  paper  but  gives  the  necessary  and  sufficient  conditions.  Math. 
Ann.,  Vol.  48,  when  A  is  symmetric  as  an  extension  of  Dr.  Taber's  theorem  for  group  G'. 

For  A  alternate  the  necessary  and  sufficient  conditions  were  given  by  Dr.  Taber  in  a 
communication  to  the  American  Academy  of  Arts  and  Sciences,  January,  1896.  (See  Pro- 
ceedings, Vol.  31,  p.  349.)  The  necessity  of  these  conditions  has  previously  been  shown  by 
Dr.  Taber  in  the  Math.  Ann.,  Vol.  46.  In  Vol.  49  (1897),  Dr.  Loewy  gave  the  conditions  as 
sufficient,  undoubtedly  without  knowledge  of  Dr.  Taber's  priority  in  the  statement  of 
this  theorem. 


78  Department  of 

|J[  ±  AM  0,  group  6r  contains  no  transformation  of  the  second  kind.  This 
theorem  leads,  for  the  case  mentioned,  to  the  following  rational  represen- 
tation of  any  transformation  of  this  group,  namely, 

where  (^A)~'^ X -\-  A~'^ X  =  0.  Moreover,  Dr.  Taber  has  shown  that  the 
sub-group  of  orthogonal  transformations  of  Cr  contains  no  transformation 
of  the  second  kind  when  A  is  alternate.^ 

The  determination  of  the  congruent  transformations  between  two  bi- 
linear forms  is  the  natural  generalization  of  the  problem  to  determine  the 
automorphic  linear  transformations  oi  A.  A  determination  of  the  trans- 
formations between  A  and  B  depending  on  the  solution  of  a  single  equa- 
tion of  degree  n  has  been  given  by  Dr.  Taber  (^Mathematical  Review^  Vol. 
1,  1897),  which  holds  for  any  case  whatever  in  which  A  and  B  are  both 
symmetric  or  both  alternate. 

The  theory  of  matrices,  or  bilinear  forms,  is  closely  related  to  the 
theory  of  Hamilton's  linear  vector  functions.  In  the  American  Journal 
of  Mathematics^  Vol.  12,  Dr.  Taber  has  given  a  development  of  the 
theory  of  matrices,  proving  many  of  the  fundamental  theorems,  from  the 
point  of  view  of  Hamilton's  theory. 

One  of  Sylvester's  most  important  contributions  to  the  theory  of 
matrices  was  a  general  formula,  given  in  the  Comptes  Rendus,  Vol.  94, 1882, 
expressing  any  power,  integral  or  fractional,  of  the  bilinear  form  or  matrix 
A  a.s  a  polynomial  in  A  of  degree  n—1.  Thus,  ii  B  =  A^^,  where  fi  is  any 
fraction,  and  if  p^,  p^,  .  .  .  p^  are  the  roots  of  the  characteristic  equation 
of  A,  we  have 

B  =  2/)'^  (^  -  P.J'yC^  -  PJ)  -"{A-  pj) 

^         (Pl-p2)iPl-p3)--<Pl-pn) 

By  means  of  this  theorem  the  determination  of  a  matrix  or  linear  substi- 
tution whose  /ith  power  is  equivalent  to  A  is  reduced  to  the  solution  of  a 
single  algebraic  equation  of  degree  n.  This  formula  was  afterwards  ex- 
tended by  Sylvester  to  any  function  of  the  matrix  A.^    Thus  we  have 

(Pi  -  PaXPi  -Ps)'--  CPi  -  Pn) 

1  See  Bull.  Am.  Math.  Soc,  Series  2,  Vol.  2,  pp.  5  and  161. 

2  Johns  Hopkins  Univ.  Circulars,  No.  28,  Vol.  3,  p.  34. 


Mathematics.  79 

Neither  of  these  formulse  applies  unless  the  roots  of  the  characteristic 
equation  of  A  are  all  distinct.  For  the  general  case,  in  which  the  roots 
of  the  characteristic  equation  have  any  given  multiplicities,  a  formula  for 
/(J.)  has  been  given  by  Dr.  Taber.^  Thus,  if  the  distinct  roots  of  the 
characteristic  equation  are  p^,  p^-,  •••  Pri  respectively  of  multiplicity  m^  mj, 
...  w„  and  if  A^'^  =  A^^'^  .••  A^.^^^A^^^^^  -  ^/'\  where  A/^  denotes 

[(^  -  pjr^  -  (pj  -  PiT^r^  •  [(  -  ^TKPj  -  PiT^^^l^ 
then 

/(.)= ££/(.)x.(.-..)^  .  --'-j^Sf^  Wis- 

For  Wj  =  Wg  =  •••  w^  =  1,  this  reduces  to  Sylvester's  formula. 

The  theory  of  matrices  stands  in  a  very  special  and  important  relation 
to  the  theory  of  higher  complex  quantity  (multiple  algebra).  Namely,  a 
class  of  systems  of  complex  numbers  with  n^  units  arises  from  the  theory 
of  lineal  transformation,  —  that  is  to  say,  a  matrix  of  n^  elements  gives 
rise  to  a  system  of  n^  units  «„•  with  the  special  multiplication  table  e^  ej/.  = 
^iki  H  ^ki  =  0  foi"  y  =^  ^'  Multiple  algebras  (systems  of  complex  numbers) 
of  this  class  have  been  termed  by  Mr.  Charles  S.  Peirce  quadrate  alge- 
bras, or  quadrates  ;  and  Peirce  has  shown  that  the  p  units  of  any  system 
of  complex  numbers  (the  p  units  of  any  multiple  algebra)  can  be  expressed 
linearly  in  terms  of  the  n^  units  of  a  quadrate  .^  Whence  it  follows  that 
the  theory  of  any  system  of  complex  numbers  is  identical  with  the  theory 
of  the  combination  by  multiplication,  addition,  and  subtraction,  of  a 
certain  system  of  p  matrices. 

The  first  quadrate  algebra,  namely,  that  with  four  units,  is  identical  with 
the  quaternions  with  the  imaginary  (Hamilton's  bi-quaternions),  as  was 
first  explicitly  pointed  out  by  Professor  Benjamin  Peirce.  That  is  to  say, 
by  substituting  for  the  original  units  e^j  a  certain  system  of  four  linearly 
independent  linear  functions  of  the  four  units  we  obtain  a  system  of  com- 
plex numbers,  1,  i,  j\  k,  which  can  be  substituted  for  the  original  units,  and 
whose  multiplication  table  is  '^  =  f  =Tc^=  -  1, 1«  =*1,  etc.,  ij  =  -ji  =  k, 
etc.  Let  now  z',  j',  k'  be  a  new  system  of  quaternion  unit  vectors  having 
the  multiplication  table  i'2  =  p  =  k'^=  -  1,  i'j'  =  -J'i'  =  k',  etc.  And 
let  a  third  system  of  units  be  formed  by  the  combination  of  these  two  sys- 

1  Math.  Ann.,  Vol.  46,  p.  568.  See  also  Proc.  Am.  Acad,  of  Arts  and  Sciences,  1893,  Vol. 
27,  p.  46  et  seq.  2  gee  Am.  Jour.  Math.,  Vol.  4,  pp.  122  and  125. 


80  Department  of 

terns,  it  being  assumed  that  each  of  the  one  system  of  quaternion  unit 
vectors  is  commutative  with  each  unit  vector  of  the  other  system.  That 
is  to  say,  that  W  =  i'i^  ij'  =j'i,  etc.  We  get  thus  sixteen  units,  1,  i,  j, 
k,  i',j',  k',  and  the  nine  binary  products  m',  if,  etc.  Dr.  Taber  has  shown 
that  the  system  of  units  thus  obtained  is  identical  with  the  quadrate  of  six- 
teen units.  The  same  is  true  if  we  had  combined  the  four  original  units 
of  the  quadrate  with  four  units,  namely,  e„  (^5  s  =  li  2)  with  a  similar 
system  of  another  quadrate,  viz.,  e'^s  (f,  s  =  1,  2),  — assuming  that  Sfte'tu 
e^,.    The  resultant  system  has  sixteen  units,  and  is  the  quadrate  with 


=  e 


tu^rt 


sixteen  units.  ^  Dr.  Taber  has  established  a  general  theorem  including 
the  one  just  given.  Namely,  he  has  shown  that,  if  w  =  mp,  the  quadrate  of 
rfi  units  is  a  compound  of  two  quadrates  severally  with  m  units  and  p  units, 
the  units  of  one  quadrate  system  being  commutative  with  each  unit  of  the 
other  quadrate.2  Whence  it  follows  that  if  the  prime  factors  of  n  are  Sj, 
^2,  •••S^,and  n  =  S^'^^B^'^^---  B^  »-,  the  quadrate  of  n^  units  is  a  compound  of  /ij 
quadrates  each  with  Sj^  units,  /ig  quadrates  each  with  ^2^  units,  etc. 

The  general  projective  group  holds  a  position  of  special  importance 
in  Lie's  theory  of  finite  continuous  groups.  For  the  adjoined  group  T  of 
any  finite  continuous  group  G,  by  means  of  which  the  sub-groups  of  G  are 
determined,  will,  if  the  equations  of  transformation  of  this  group  are 
properly  chosen,  appear  as  a  sub-group  of  the  general  projective  group. 
Thus  the  theory  of  matrices  is  of  importance  in  the  investigation  of 
certain  problems  of  Lie's  theory,  since  this  calculus  furnishes  a  convenient 
instrument  for  the  treatment  of  the  general  projective  group. 

The  chief  theorem  of  Lie's  theory  states  that  if  a  system  of  infinitesi- 
mal transformations  satisfies  certain  conditions,  they  generate  a  group 
with  continuous  parameters,  each  of  whose  finite  transformations  can  be 
generated  by  an  infinitesimal  transformation  of  the  group. ^  In  1892 
Professor  Study  made  the  extremely  important  discovery  that  this 
theorem  is  subject  to  certain  limitations,  —  showing  that  an  exception  to 
this  theorem  existed  in  the  case  of  the  special  linear  homogeneous  group  in 

1  Am.  Jour.  Math.,  Vol.  12,  p.  391. 

2  Ibid.  This  theorem  was  obtained  independently,  but  subsequently,  by  Professor  Study. 
See  "  Math.  Papers  of  Internat.  Math.  Congress  of  1893,"  p.  378. 

8  Transformationsgruppen,  Vol.  1,  pp.  75,  158  ;  Continuierliche  Gruppen,  p.  390.  Lie 
originally  defined  a  finite  continuous  group,  substantially  {Trans.  Grp.,  p.  3),  as  a  group  with 
continuous  parameters.  Ultimately,  he  assumed  that  in  a  continuous  group  as  thus  defined 
each  transformation  can  be  generated  by  an  infinitesimal  transformation  of  the  group  ( Con- 
tin.  Grp.,  p.  379). 


Mathematics.  81 

two  variables,  namely,  that  not  every  transformation  of  this  group  can  be 
generated  by  an  infinitesimal  transformation  of  the  group. ^  Subsequently, 
in  1893  (^Am.  Jour.  Math.,  Vol.  16),  Dr.  Taber  showed  that  the  orthogonal 
group  in  n  variables  (for  »i  ^  4)  also  presents  an  exception  to  Lie's 
theorem;  and  in  1895  gave,  in  a  communication  to  the  American  Academy 
of  Arts  and  Sciences,  the  conditions  necessary  and  sufficient  that  a  proper 
orthogonal  substitution  may  be  generated  by  an  infinitesimal  orthogonal 
substitution. 2 

For  n>  2  also,  the  special  linear  homogeneous  group  in  n  variables  is 
continuous  only  in  the  neighborhood  of  the  identical  transformations. 
For  two  variables,  Study  gave  the  conditions  necessary  and  sufficient  that 
a  transformation  of  this  group  may  be  generated  by  an  infinitesimal  trans- 
formation of  this  group.  Dr.  Taber  gave,  in  1896  (^Bull.  Am.  Math.  Soc, 
Series  2,  Vol.  2,  p.  231),  these  conditions  for  n  variables ;  also  the  conditions 
necessary  and  sufficient  that  a  transformation  of  the  special  linear  homo- 
geneous group  may  be  the  mth  power  of  a  transformation  of  this  group. 
From  these  conditions  it  appears  that  the  nth.  power  of  any  transforma- 
tion of  this  group  can  be  generated  by  an  infinitesimal  transformation  of 
this  group;  and  that  the  transformations  of  this  group  can  be  divided  into 
as  many  genera  as  there  are  prime  factors  of  n.  Thus,  if  8  is  a  prime 
factor  of  n,  there  are  transformations  of  this  group  whose  w/Sth  power,  but 
no  lower  power,  can  be  generated  thus.^ 

Dr.  Taber  has  shown  that  the  following  groups  are  not  continuous, 
except  in  the  neighborhood  of  the  identical  transformations,  namely,  the 
group  Gr,  mentioned  above,  for  A  symmetric  or  alternate,  and  in  general 
when  A  is  neither  symmetric  nor  alternate,  provided  either  |  J^  4-  J.  |  or 
1  J.  —  ^  I  is  equal  to  zero.^  For  all  these  groups  the  infinitesimal  trans- 
formations satisfy  Lie's  criterion. 

Dr.  Taber  has  also  shown  that  the  following  groups  are  continuous, 
namely,  group  Gr  when  \A±A\=^0,  the  sub-group  of  orthogonal  trans- 
formations of  6r,  for  A  alternate,  and  the  group  of  automorphic  linear 

n         n 

transformations  of  a  bilinear  form  A=y^   P^'if^iVi'^  of  non-zero  deter- 

1       1 
minant,  the  rr's  and  y's  being  contra-gredient.^ 

1  Leipzige  Berichte,  1892. 

2  See  Proc,  Vol.  30,  p.  551.     This  result  is  referred  to  above  on  p.  77. 

8  See  Bull.  Am.  Math.  Soc,  Series  2,  Vol.  3,  p.  9.  *  See  p.  77,  note  1. 

6  See  p.  77  above,  also  Proc.  Am.  Acad.  Arts  and  Sciences,  Vol.  31,  p.  181. 

G 


82  Department  of 

Investigations  upon  the  continuity  of  the  groups  in  two  and  three 
variables  have  been  carried  on  under  Dr.  Taber's  supervision  by  certain 
of  the  students  in  the  mathematical  department.  Dr.  E.  G.  Rettger  has 
investigated  the  continuity  of  all  the  two  and  three  fold  groups,  fifty-nine 
in  number,  enumerated  by  Lie,  Continuierliche  Gruppen,  pp.  288  and  519 ; 
and  shown  that  twenty-one  of  these  groups  are  discontinuous. ^  Mr.  F. 
P.  Williams  has  investigated  the  continuity  of  certain  groups  of  the 
plane,  not  treated  by  Mr.  Rettger;  and  Mr.  S.  E.  Slocum  has  pointed 
out  the  nature  of  Lie's  error  in  his  demonstration  of  the  fundamental 
theorem  referred  to  above. ^ 

If  a  system  of  real  infinitesimal  transformations  satisfy  a  modification 
of  the  Lieschen  criterion,  Lie  states  that  they  generate  a  real  continuous 
group,  that  is,  a  group  with  continuous  parameters,  each  transformation  of 
which  can  be  generated  by  an  infinitesimal  transformation  of  the  group. 
But  this  theorem  is  subject  to  certain  modifications. 

Dr.  Taber  has  shown  that  the  group  of  real  proper  orthogonal  trans- 
formations is  continuous; 3  also  that  in  the  groups  of  real  transforma- 
tions enumerated  below  not  every  transformation  can  be  generated  by  an 
infinitesimal  transformation  of  the  group,  namely,  — 

the  real  projective  group,* 
the  general  and  special  real  linear  groups, 
the  general  and  the  special  real  linear  homogeneous  groups, 
the  sub-group  of  real  transformations  of  Cr,  for  A  real  and  either 
alternate  or  symmetric. 

Further,  that  if  G  denotes  either  of  the  groups  just  enumerated,  the  first 
part  (I)  of  the  theorem  of  p.  77  holds.  And  he  has  given  the  con- 
ditions necessary  and  sufficient,  for  each  of  the  first  three  of  the  groups 
just  enumerated,  that  a  transformation  of  this  group  may  be  generated  by 
an  infinitesimal  transformation  of  this  group. ^ 

Let  G  denote  a  group  generated  by  the  composition  of  r  one-fold 

1  Proc.  Am.  Acad,  of  Arts  and  Sciences,  Vol.  33. 

2  See  papers  to  appear  in  Vol.  35  of  the  Proc.  Am.  Acad,  of  Arts  and  Sciences. 

8  Bull.  Am.  Math.  Soc.  for  July,  1894.  See  also  Proc.  Am.  Acad,  of  Arts  and  Sciences, 
Vol.  27,  p.  163. 

4  For  the  real  projective  group  this  was  first  pointed  out  by  Professor  H.  B.  Newson, 
Kansas  Univ.  Quart.,  1896. 

6  B7iU.  Am.  Math.  Soc,  Series  2,  Vol.  2,  p.  228  et  seq.  Also  Proc.  Am.  Acad,  of  Arts 
and  Sciences,  Vol.  31,  p.  336,  and  Vol.  32,  p.  77. 


^y\ 


Mathematics.  83 

groups  (each  containing  the  identical  transformation),  namely,  Gri<^\  G/^\ 
•••G/''\  whose  infinitesimal  transformations  satisfy  Lie's  criterion.  It  may 
happen  that  a  transformation  T  of  one  (or  more)  of  these  one-fold 
groups,  as  G/'^\  combined  with  any  transformation  of  another  of  the  one- 
fold sub-groups,  as  Gi^"^  (in  particular  with  the  infinitesimal  transforma- 
tion of  Gi^"^),  results  in  a  transformation  that  cannot  be  generated  by  an 
infinitesimal  transformation  of  G.  Any  such  transformation  T,  together 
with  any  transformation  T  of  G  that  cannot  be  generated  by  an  infinitesi- 
mal transformation  of  this  group,  may  be  termed  singular;  all  other 
transformations  of  G  will  then  be  non-singular.  In  a  paper,  of  which  an 
abstract  was  read  at  the  February  meeting  of  the  American  Mathematical 
Society,  1899,  Dr.  Taber  showed  that,  if  G  is  a  sub-group  of  the  projective 
group,  any  singular  transformation  of  G  can  always  be  obtained  by  the 
composition  of  two  non-singular  transformations  of  G ;  and  moreover 
that,  if  T  is  any  singular  transformation  of  G  not  generated  by  an  infini- 
tesimal transformation  of  G,  a  transformation  Tp^  generated  by  an  infini- 
tesimal transformation  of  G,  can  always  be  found  which  can  be  made  to 
approach  as  nearly  as  we  please  to  T  by  taking  p  sufQciently  small,  so 
that    limp^o  Tp  =  T. 


DEPARTMENT   OF   PHYSICS. 

By  Arthur  Gordon  Webster. 

STAFF. 

Albert  Abraham  Michelson,  Ph.D.,  Professor  of  Physics,  1889-92. 
Arthur  Gordon  Webster,  Ph.D.,  Docent  in  Mathematical  Physics,  1890-92  ; 
Assistant  Professor  of  Physics,  1892-. 

FELLOWS  AND  SCHOLARS. 

Louis  W.  Austin,  Scholar  in  Physics,  1890-91 ;  Fellow,  1891-92. 

Frank  K.  Bailey,  Scholar  in  Physics,  1898-99. 

William  P.  Boynton,  Scholar  in  Physics,  1894-95 ;  Fellow,  1895-97. 

Arthur  L.  Clark,  Scholar  in  Physics,  1896-97 ;  Fellow,  1897-98. 

D.  Ellis  Douty,  Scholar  in  Physics,  1898-99. 

William  F.  Durand,  Scholar  in  Physics,  Nov.-Dec,  1889. 

Thomas  W.  Edmondson,  Fellow  in  Physics,  1894-96. 

Benjamin  F.  Ellis,  Scholar  in  Physics,  1892-93. 

T.  Proctor  Hall,  Scholar  in  Physics,  1890-91 ;  Fellow,  1891-93. 

fBENjAMiN  C.  HiNDE,  Fcllow  and  Assistant  in  Physics,  1892-93.     Died  Feb. 

6,  1894. 
Richard  J.  Holland,  Ph.D.,  Honorary  Fellow  in  Physics,  1893-94. 
James  Edmund  Ives,  Scholar  in  Physics,  1897-98 ;  Fellow,  1898-. 
Sidney  J.  Lochner,  Scholar  in  Physics,  1892-93. 
Alexander  McAdie,  Fellow  in  Physics,  1889-90. 
Alfred  G.  Mayer,  Assistant  in  Physics,  1889-90. 
EoLLA  R.  Ramsey,  Scholar  in  Physics,  1898-99. 
Stanley  H.  Rood,  Scholar  in  Physics,  1893-94. 

t  Clarence  A.  Saunders,  Fellow  in  Physics,  1892-95.     Died  Dec.  19,  1898. 
Benjamin  F.  Sharpe,  Fellow  in  Physics,  1894-96 ;  1897-98. 
Robert  R.  Tatnall,  Ph.D.,  Honorary  Fellow  in  Physics,  1897-98. 
Samuel  N.  Taylor,  Fellow  in  Physics,  1893-96. 

Frank  L.  0.  Wadsworth,  Fellow  in  Physics,  1889-90;   Assistant,  1890-92. 
Arthur  J.  Warner,  Scholar  in  Physics,  1889-90. 
Albert  P.  Wills,  Scholar  in  Physics,  1894-95 ;  Fellow,  1895-97. 

85 


86  Department  of 


SPECIAL   STUDENTS. 


Ervin  W.  Howard,  1892-93. 
Albert  B.  Kimball,  1893-94. 
William  Nelson,  1892-93. 
Joseph  0.  Phelon,  1892-93. 


Arthur  L.  Rice,  1892-93. 
Stanley  H.  Rood,  1892-93. 
Clayton  0.  Smith,  1892-93. 
Hugh  M.  Southgate,  1892-93. 


The  work  of  a  Department  of  Physics  in  a  university  at  the  present 
time  may  be  best  understood  after  a  brief  survey  of  some  of  the  chief 
achievements  of  the  science  during  the  present  century.  As  we  in  this 
country  have  our  attention  called  more  frequently  to  the  achievements  of 
applied  than  to  those  of  pure  science,  it  is  worth  while  to  dwell  somewhat 
upon  the  influence  of  pure  science  upon  applied,  and  upon  its  contribution 
to  the  progress  of  civilization.  At  the  beginning  of  the  century,  the 
various  subjects  that  together  make  up  the  science  of  Physics  were  in  a 
very  imperfect  state.  Of  heat,  light,  sound,  electricity,  and  magnetism, 
little  that  we  now  accept  was  known,  while  of  that  little  still  less  had 
been  applied  to  practical  matters.  The  science  of  mechanics,  upon  which 
the  whole  superstructure  of  physics  must  inevitably  rest,  had  indeed  been 
set  upon  a  firm  basis  by  the  immortal  Newton,  while  its  principles  had 
recently  been  formulated  by  the  distinguished  mathematician  Lagrange, 
in  a  way  so  broad  and  powerful  that  it  has  not  since  been  improved  upon. 
The  science  of  pure  mathematics  had  of  course  arrived  at  a  high  degree 
of  perfection,  and  many  of  the  leading  mathematicians  had  devoted  their 
best  efforts  to  the  subject  of  mechanics.  But  while  a  large  number  of 
investigators  had  laid  the  foundations  of  our  present  knowledge  by  the 
method  of  experiment,  the  habit  of  questioning  nature,  instruments  in 
hand,  had  as  yet  by  no  means  become  general.  This  habit  of  direct 
experimental  research  is  certainly  in  large  degree  to  be  credited  to  the 
present  century.  Without  stopping  to  enumerate  the  leading  achieve- 
ments of  physics  during  the  century,  let  us  take  as  illustrations  a  few 
leading  cases.  Nothing  has,  perhaps,  done  more  to  change  the  face  of 
the  earth,  from  the  point  of  view  of  man,  than  the  invention  of  the  steam- 
engine  and  of  the  railway  thereby  made  possible,  of  the  telegraph  and 
telephone,  while  the  transmission  of  energy  by  electricity  bids  fair  to 
rival  them  in  importance.     Let  us  then  briefly  consider  what  led  to  these 


Physics.  87 

inventions.  At  the  beginning  of  the  century  it  was  universally  held  that 
heat  was  a  substance,  which  could  be  put  into,  or  removed  from,  ordinary 
matter.  It  is  to  the  experiments  of  one  of  our  own  countrymen,  the 
celebrated  Count  Rumford,  that  was  due  the  original  assault  on  this 
notion,  the  last  blow  at  which  was  delivered  by  the  Englishman,  James 
Prescott  Joule,  in  his  great  discovery  of  the  mutual  convertibility  of  heat 
and  mechanical  work,  and  of  the  doctrine  of  the  Conservation  of  Energy. 
This  discovery,  so  simple  that  it  may  be  understood  by  every  one,  namely, 
that  for  whatever  we  do  we  get  an  exact  equivalent,  neither  more  nor 
less,  is  the  fundamental  truth  of  physical  science.  It  is  in  physics  the 
supreme  achievement  of  the  century.  Until  it  was  discovered,  a  true 
understanding  of  the  principles  of  the  steam-engine  could  not  be  arrived 
at,  although  the  way  had  been  prepared  by  the  theoretical  work  of  a 
French  engineer,  the  illustrious  Sadi  Carnot.  To  Carnot  and  Joule,  then, 
we  owe  the  two  laws  of  the  new  science  of  Thermodynamics,  or  the 
relations  between  heat  and  work,  which  lie  at  the  basis  of  all  steam, 
gas,  oil,  or  other  heat  engines,  as  well  as  of  all  freezing  machines,  and 
of  transmission  or  storage  of  energy  by  means  of  compressed  gases. 
It  would  be  well,  therefore,  for  all  intending  investors  in  new  and 
promising  compressed  or  liquid  air  companies,  no  matter  how  attrac- 
tively advertised,  to  find  out  what  thermodynamics  has  to  say  of  the 
propositions  advanced. 

The  foundations  having  been  laid  by  the  experimental  work  of  Joule 
and  the  theoretical  work  of  Carnot,  the  required  knowledge  of  the  prop- 
erties of  steam  and  other  vapors  used  in  engines  and  cooling  machines 
was  furnished  by  a  masterly  series  of  experimental  researches  of  the  dis- 
tinguished French  physicist,  Henri  Regnault,  who  was  set  at  work  by 
the  French  government,  and  whose  work  has  ever  since  been  classical. 
No  engineer  could  to-day  design  an  engine  without  making  use  of  the 
data  thus  furnished. 

Let  us  pass  on  to  the  telegraph.  Here  again  it  was  the  patient  work 
of  our  countryman  Henry,  working  quietly  with  purely  scientific  aims  in 
his  little  laboratory  in  Albany,  —  it  was  Henry's  investigations  on  the 
electromagnet  that  made  feasible  the  invention  by  Morse  of  the  recording 
telegraph,  which  is  still  in  use  more  than  any  other  system  all  over  the 
world.  It  is,  however,  when  we  come  to  the  great  question  of  submarine 
telegraphy  that  we  see  most  emphatically  the  practical  contribution  of 
pure  science.     The  problem  of  telegraphing  through  an  insulated  wire 


88  Department  of 

immersed  in  water  is  totally  different  from  the  corresponding  one  for  a 
land  line,  and  for  years  seemed  hopeless  of  solution.  The  construction  of 
a  cable  reaching  from  Europe  to  America  was  such  a  costly  undertaking 
as  to  deter  the  most  venturesome  capitalists,  unless  they  could  be  pre- 
viously furnished  with  a  reasonable  guarantee  of  success.  It  was  here 
that  the  work  of  William  Thomson,  to-day  known  as  Lord  Kelvin,  our 
greatest  living  physicist,  furnished  the  necessary  assurance.  Taking  up 
the  purely  mathematical  problem  of  the  propagation  of  an  electrical 
impulse  in  a  submarine  cable,  he  for  the  first  time  set  its  mode  of  work- 
ing in  a  clear  light,  and  by  means  of  his  solution  predicted  that  the 
American  cable,  if  constructed  in  accordance  with  his  specifications,  was 
bound  to  work.  Led  by  faith  in  this  statement,  Cyrus  W.  Field  col- 
lected the  money,  the  cable  was  laid,  and  the  cable  worked.  That  the 
first  cable  of  1858  lasted  but  little  more  than  a  month  was  due  to  the 
unfortunate  mode  of  working  adopted  by  the  chief  electrician,  a  so-called 
practical  man,  who  would  however  have  been  much  better  off  if  he  had 
possessed  the  theoretical  knowledge  of  Professor  Thomson.  To-day 
twelve  working  cables  span  the  Atlantic,  representing  an  investment  of 
eighty-five  million  dollars.  Is  this  too  large  a  sum  to  credit  to  theoretical 
physics  ?  The  problem  of  telegraphy  that  is  to-day  most  interesting  is 
that  of  telephoning  across  the  Atlantic,  and  I  feel  no  hesitation  in  saying 
that  before  this  can  be  accomplished  a  large  amount  of  theoretical  research 
will  be  necessary,  together  with  such  experimental  work  as  may  be  car- 
ried on  in  laboratories  like  ours,  and  is  now  being  carried  on  by  Professor 
Pupin  of  Columbia  University,  before  a  single  dollar  is  sunk  under  the 
sea. 

The  question  of  electric  power  transmission  is  one  whose  genesis  is 
easy  for  all  to  remember.  All  do  not  remember,  however,  that  far  from 
electrical  science  being,  as  the  newspapers  maintain,  in  its  infancy,  the 
laws  governing  our  dj^namos  and  motors  were  discovered  in  the  first  quar- 
ter of  the  century,  mainly  by  two  princes  among  workers  in  physics,  the 
Frenchman  Ampere  and  the  Englishman  Faraday.  The  achievement  of 
Ampere  in  discovering  the  laws  of  the  action  of  electrical  currents  in 
producing  magnetic  forces  upon  each  other  was,  in  its  combination  of 
mathematical  and  experimental  brilliancy,  one  of  the  most  remarkable 
achievements  in  the  annals  of  science.  Still  more  important  practically 
were  the  discoveries  of  Faraday,  who  deduced  unaided  all  the  laws  upon 
which  the  working  of  dynamo-machines  depends. 


Physics.  89 

Another  illustration  of  our  point  is  the  wireless  telegraphy  of  Mar- 
coni, of  which  we  hear  so  much  in  the  newspapers  to-day.  What  the 
newspapers  do  not  tell  us  is  that  the  electrical  waves  made  use  of  in  tele- 
graphing across  the  English  Channel  were  predicted  in  a  paper  published 
in  1864  by  the  great  English  physicist,  Clerk-Maxwell,  who  completely 
remodelled  the  theory  of  electricity  as  it  then  existed.  Twenty-three 
years  afterward  his  predictions  were  experimentally  verified  by  Hein- 
rich  Hertz,  who  thus  rendered  the  practical  results  of  Marconi  possible. 

These  researches,  far-reaching  as  were  their  practical  results,  were 
carried  on  by  purely  scientific  workers,  solely  for  the  interest  that  they 
presented  by  increasing  our  knowledge.  This  should  always  be  the  posi- 
tion of  the  scientist,  for,  if  he  turns  aside,  attracted  by  the  seductive 
paths  of  moneymaking,  he  is  almost  sure  to  lose  the  prize  of  the  great 
discovery. 

Let  us  now  turn  to  the  present  means  of  advancing  our  scientific 
knowledge.  It  is  not  to  be  overlooked  that  many  of  the  great  discoveries 
above  mentioned  were  made  with  very  simple  apparatus  and  with  very 
modest  facilities.  When  we  see  the  very  primitive  instruments  of 
Ampere,  Henry,  and  Faraday,  we  are  led  to  wonder  that  they  could  pro- 
duce such  accurate  results.  The  days  of  such  work  are  however  over. 
It  is  now  possible  to  add  to  the  knowledge  already  so  richly  harvested 
only  by  experiments  of  the  most  careful  nature  and  by  measurements  of 
great  refinement,  involving  often  complicated  and  expensive  apparatus. 
It  is  for  this  reason  that  the  great  laboratories  have  sprung  up,  which  we 
find  in  such  large  numbers  both  in  this  country  and  in  Europe.  Until 
about  a  quarter  of  a  century  ago  there  were  none.  It  had,  however,  come 
to  be  recognized  that,  in  order  to  make  an  investigator  of  a  student,  it  was 
necessary  not  only  that  he  should  hear  lectures,  but  that  he  should  him- 
self have  practice  in  experimentation  and  in  the  making  of  exact  meas- 
urements. For  these  purposes,  courses  of  instruction  in  physical  measure- 
ments were  planned,  and  laboratories  where  they  might  be  practically 
carried  on  were  erected.  One  of  the  earliest  of  these  teaching  labora- 
tories was  that  of  the  Massachusetts  Institute  of  Technology,  presided  over 
by  Professor  Pickering,  now  director  of  the  Harvard  College  Observatory. 
Later  came  the  laboratories  at  Yale,  Harvard,  Cornell,  Johns  Hopkins, 
Chicago,  and  Columbia,  costing  between  one  and  two  hundred  thousand 
dollars  each.  In  each  case  is  to  be  added  the  sum  of  from  twenty  to 
fifty  thousand  dollars  for  equipment  with  apparatus.     During  the  same 


90  Department  of 

time  a  large  number  of  physical  laboratories  have  been  built  in  Europe, 
some  of  them  involving  a  still  larger  expenditure  of  money,  notably  the 
one  at  Ziirich,  in  which  the  Swiss  government  invested  about  a  quarter 
of  a  million  of  dollars.  At  all  these  laboratories  both  teaching  and  the 
performance  of  research  were  contemplated,  and  an  idea  of  the  results 
achieved  may  be  obtained  from  the  statement  that  from  the  Johns  Hop- 
kins laboratory  have  issued  upwards  of  five  hundred  papers,  and  from  those 
of  Harvard  and  Cornell  in  the  neighborhood  of  one  hundred  each. 

Besides  these  institutions  so  immediately  connected  with  teaching, 
another  type  of  laboratory  has  made  its  appearance  within  the  last  ten 
years.  Of  this  the  most  conspicuous  example  is  the  German  Imperial 
Physico-technical  Institute,  which  is  separated  from  teaching,  and  is 
intended  solely  for  the  performance  of  research,  especially  for  the  per- 
formance of  such  measurements  as  would  require  resources  exceeding 
those  possessed  by  private  or  university  laboratories.  The  work  per- 
formed in  this  great  institution  has  been  of  the  highest  class,  and  has 
drawn  the  attention  of  other  governments  to  the  desirability  of  establish- 
ing such  national  laboratories,  with  the  result  that  England  has  now  fol- 
lowed the  example  of  Germany,  though  upon  a  smaller  scale.  A  further 
example  is  presented  in  the  Faraday-Davy  research  laboratory  in  London, 
the  gift  of  a  private  individual,  Mr.  Ludwig  Mond,  a  successful  technical 
chemist,  who  in  this  most  appropriate  manner  recognized  the  debt  of 
applied  to  pure  science  by  the  foundation  of  a  laboratory  devoted  espe- 
cially to  the  furtherance  of  research  in  physical  chemistry. 

What,  then,  has  been  the  position  occupied  by  Clark  University  in 
the  ranks  of  this  march  of  progress?  Naturally  it  has  been  a  modest  one. 
Without  a  separate  laboratory  building,  with  a  small  equipment,  and  a 
staff  reduced  to  the  minimum,  it  has  of  course  not  been  able  to  rival  in 
quantity  the  work  of  its  greater  predecessors.  It  may,  however,  be  re- 
marked that  limitations  of  size  are  not  necessarily  limitations  of  quality. 
The  relatively  small  number  of  students  coming  here  have  received  greater 
individual  attention  than  would  have  been  possible  at  more  crowded 
institutions.  In  spite  of  our  limited  space  and  equipment,  it  has  alwaj'^s 
been  found  possible  to  put  in  possession  of  each  student  apparatus  suitable 
for  the  performance  of  original  research,  and  to  give  him  what  is  more 
important,  minute  personal  direction  and  encouragement.  In  this  manner 
students  coming  to  us  from  the  colleges,  often  ill  prepared  for  the  severe 
mathematical  work  so  necessary  to  the  physicist,  but  to  which  they  have 


Physics.  91 

been  little  accustomed,  are  rapidly  pushed  on,  and  recover  their  places  in 
line. 

The  Department  of  Physics  was,  during  the  first  three  years  of  the 
history  of  the  University,  under  the  direction  of  the  distinguished  physi- 
cist, Professor  Albert  A.  Michelson,  who  was  then  called  from  it  to  take 
the  conduct  of  the  larger  department  at  the  University  of  Chicago. 
During  his  stay  at  Clark  Professor  Michelson  was  engaged  in  research 
in  the  field  of  optics,  inventing  a  method  for  the  study  of  radiations  from 
both  celestial  and  terrestrial  bodies,  by  means  of  an  instrument  devised 
by  him,  and  depending  on  the  interference  of  light.  By  means  of  this 
ingenious  and  elegant  method,  valuable  results  in  connection  with  spec- 
troscopy and  the  measurement  of  small  astronomical  objects  were  obtained, 
upon  which  a  number  of  papers  were  published.  Before  the  termination 
of  his  labors  here.  Professor  Michelson  was  invited  by  the  International 
Bureau  of  Weights  and  Measures  to  make,  by  means  of  his  new  apparatus, 
a  comparison  between  the  international  standard  of  length  and  the  length 
of  a  certain  wave  of  light,  thus  establishing  a  natural  unit  of  length. 
A  new  apparatus  having  been  designed  and  constructed  under  the  direc- 
tion of  Mr.  F.  L.  O.  Wadsworth,  preliminary  observations  were  made  at 
the  University,  and,  obtaining  leave  of  absence.  Professor  Michelson  and 
Mr.  Wadsworth  proceeded  to  Paris,  where  the  experiment  was  carried 
out  with  marked  success,  constituting  a  performance  in  metrology  that 
will  undoubtedly  become  classical. 

During  his  conduct  of  the  department.  Professor  Michelson  delivered 
usually  one  lecture  a  week,  on  various  subjects  concerning  the  Theory 
of  Light,  especially  connected  with  his  own  researches.  Upon  the  be- 
ginning of  the  incumbency  of  the  writer,  a  consecutive  course  in  theoreti- 
cal or  mathematical  physics  was  planned,  and  has  been  regularly  delivered, 
the  course  covering  five  lectures  a  week  for  a  term  of  two  years.  Per- 
haps the  principal  claim  that  can  be  made  for  the  department  is  the  stress 
that  has  been  laid  upon  the  subject  of  mathematical  physics,  undoubtedly 
the  most  difficult  branch  for  the  student,  and  one  which  has  not  yet  be- 
come popular  in  this  country,  yet  which  is  of  prime  importance,  and 
without  which  none  can  hope  to  reach  the  highest  position  in  the  science. 
A  gratifying  testimonial  to  the  truth  of  this  contention  is  furnished  by 
the  recent  arrival  at  the  University  of  two  students,  both  doctors  of  phi- 
losophy from  German  universities,  who  have  come  here  impressed  with 
their  need  for  more  study  of  mathematical  physics. 


92  .  Department  of 

In  this  course  the  several  parts  of  the  subject  are  treated  in  regular 
order,  as  parts  of  a  logically  connected  whole,  starting  from  the  funda- 
mental basis  of  dynamics.  The  course  is  attended  by  every  student  in 
the  department,  and  he  is  held  responsible  for  a  knowledge  of  its  subject- 
matter  in  his  examination  for  the  doctor's  degree.  It  is  safe  to  say  that 
in  this  respect  the  requirement  for  the  degree  is  not  exceeded  at  any 
institution  in  the  country.  The  regular  courses  of  the  cycle  are  as 
follows  :  — 

1.  Dynamics.  —  General  Methods,  Canonical  Equations,  Methods  of  Hamil- 
ton and  Jacobi,  Systems  of  Particles,  Eigid  Bodies. 

2.  Newtonian  and  Logarithmic  Potential  Fmictions,  Attraction  of  Ellipsoids. 

3.  Elasticity,  Hydrodynamics,  Wave  and  Vortex  Motion,  Dynamical  Basis 
of  Sound  and  Light. 

4.  Electricity  and  Magnetism. 

5.  Optics,  Physical  and  Geometrical.  —  Elastic  and  Electromagnetic  Wave- 
theories. 

6.  Thermodynamics,  Thermo-  and  Electro-Chemistry,  Kinetic  Theory  of 
Gases. 

7.  The  Partial  Differential  Equations  of  Mathematical  Physics. 
Laplace's  Equation,  Equation  of   Thermal   and  Electrical  Conduction, 

Equation  of  Wave-motion,  Telegrapher's  Equation,  Developments  in 
Series,  Legendre's,  Laplace's,  Bessel's,  and  Lame's  Functions. 

Besides  these,  it  has  been  the  practice  to  deliver  each  year  at  least  one 
new  course,  so  that  certain  courses  are  delivered  occasionally.  A  num- 
ber of  courses  in  pure  mathematics  have  also  been  delivered  at  various 
times,  supplementing  those  of  the  mathematical  department.  These 
extra  courses  have  been  as  follows  :  — 

Dynamics  of  Cyclic  and  Oscillatory  Systems,  with  applications  to  the  The- 
ory of  Electricity,  Sound,  and  Light. 

Comparison  of  the  Theories  of  the  Ether. 

Theory  of  Functions  of  Real  and  Complex  Variables. 

Definite  Integrals,  Fourier's  Series. 

Ordinary  Differential  Equations. 

Linear  Differential  Equations,  particularly  of  the  second  order. 

Elliptic  Functions  (notation  of  Weierstrass),  with  certain  physical  applica- 
tions, including  the  theory  of  the  Top. 

Orthogonal  Surfaces  and  Curvilinear  Coordinates,  and  their  applications. 

Of  the  lectures  in  the  above  course  one  volume,  on  the  theory  of  elec- 
tricity and  magnetism,  has  been  published,  and  has  apparently  been  of  use 


Physics.  93 

to  teachers  in  other  institutions.  Other  volumes  are  in  course  of  prep- 
aration. 

In  addition  to  the  lectures,  a  weekly  colloquium  or  meeting  for  the 
discussion  of  questions  in  experimental  physics  has  been  held.  Here 
reports  upon  current  articles  in  the  leading  physical  journals  are  deliv- 
ered by  the  students,  and  the  most  important  classical  determinations  are 
also  taken  up,  in  order  that  familiarity  may  be  gained  with  the  methods 
of  the  masters  of  research.  These  meetings  have  been  of  great  help  to 
students,  and  have  given  them  practice  in  presenting  their  ideas  before 
an  auditory.  Beside  the  work  of  instruction,  research  has  been  carried 
on  in  the  laboratory  by  every  student  and  the  professor.  When  a  stu- 
dent arrives  at  the  University  he  is  at  first  put  at  work  upon  a  subject 
designed  to  test  his  powers,  and  to  give  him  familiarity  with  the  princi- 
ples of  exact  measurement.  When  he  has  shown  his  ability,  he  is  encour- 
aged to  undertake  a  research  for  himself,  under  the  continual  guidance 
of  the  professor.  In  this  way  the  undertaking  of  research  before  the 
necessary  experience  has  been  gained  is  prevented,  and  the  publication  of 
trifling  or  ill-considered  articles  is  discouraged.  As  a  rule  a  student 
devotes  at  least  two  years  to  the  preparation  of  a  doctor's  dissertation. 
Thus  the  number  of  published  researches  is  limited.  Six  doctor's  disser- 
tations have  been  published,  and  another  is  ready  for  publication.  Be- 
side these  a  number  of  other  researches,  both  theoretical  and  experimental, 
have  been  published,  one  of  which  latter  was  honored  by  a  substantial 
money  prize  in  an  international  competition.  These  researches  have  not 
been  confined  to  any  one  branch  of  physics,  but  have  dealt  with  molecular 
physics,  electricity,  magnetism,  and  sound.  Most  of  them  have  been  of 
such  a  nature  that  the  student  was  forced,  not  to  work  in  a  single  narrow 
specialized  line,  but  to  gain  a  large  amount  of  experience  in  various  parts 
of  the  subject.  A  research  of  this  nature  is  of  far  more  value  to  the 
student  than  one  performed  simply  for  the  purpose  of  gaining  him  a  de- 
gree, and  dealing  only  with  a  narrow  range  of  ideas. 

The  subjects  of  the  dissertations  have  been  as  follows  :  Mr.  T.  P.  Hall 
worked  out  a  new  method  for  the  determination  of  the  surface  tension 
of  liquids,  suggested  by  Professor  Michelson,  in  which  the  pull  upon  a 
film  of  liquid  was  directly  weighed  by  a  balance.  Mr.  C.  A.  Saunders 
made  a  determination  of  the  velocity  of  electric  waves  in  parallel  wires, 
by  a  direct  method,  in  which  the  wave-length  and  period  of  the  waves 
were  measured,  the  latter  by  photographing  the  periodic  spark  giving 


94  Department  of 

rise  to  the  wave  by  means  of  a  revolving  Foucault  mirror,  the  wave- 
length by  measuring  the  length  of  the  wires,  which  was  made  to  be  a 
quarter  wave-length  by  means  of  electrical  resonance.  This  research 
demanded  a  large  amount  of  time,  and  elaborate  apparatus.  In  connec- 
tion with  the  revolving  mirror  a  convenient  method  devised  by  the  writer 
for  maintaining  a  constant  angular  velocity  was  made  use  of.  Mr.  T.  W. 
Edmondson  determined  the  distances  necessary  for  the  formation  of  a 
spark  at  varying  potentials  between  spheres  of  different  sizes  in  air  and 
in  various  insulating  liquids,  the  potentials  being  measured  by  means  of 
an  absolute  attracted  disk  electrometer.  Mr.  S.  N.  Taylor  made  a  com- 
parison between  the  important  cadmium  element  devised  by  Weston  with 
the  well-known  Latimer  Clark  standard  cell,  in  which  he  compared  their 
electromotive  forces  by  means  of  an  electro-dynamometer,  obtaining 
results  agreeing  remarkably  well  with  those  obtained  by  a  quite  different 
method  at  the  German  Reichsanstalt.  Mr.  W.  P.  Boynton  carried  out 
an  experimental  verification  of  the  theory  of  the  action  of  the  peculiar 
high-frequency  induction  coil  invented  by  Elihu  Thomson  and  Tesla, 
which  had  never  been  mathematically  treated  in  detail,  not  to  say  experi- 
mented upon.  This  work  involved  a  large  number  of  difficult  measure- 
ments, including  the  currents,  potentials,  and  frequencies  of  oscillation 
involved  in  the  working  of  the  apparatus.  The  results  were  in  excellent 
agreement  with  the  theory,  considering  the  difficulty  of  the  experiments. 
Mr.  A.  P.  Wills  undertook  the  development  of  a  new  and  ingenious 
method,  suggested  by  the  writer,  but  materially  improved  by  him,  for 
measuring  the  magnetic  permeability  of  substances,  whether  magnetic 
or  diamagnetic,  differing  so  little  in  this  respect  from  air  as  to  be  not 
amenable  to  the  usual  methods.  By  means  of  a  simple  arrangement 
involving  the  use  of  a  slab  of  the  substance  suspended  in  the  field  of  a 
powerful  electromagnet  with  peculiarly  shaped  pole-pieces,  the  effect  was 
measured  by  the  pull  on  a  sensitive  balance,  so  that  accurate  results  were 
easily  obtained.  This  work  of  Mr.  Wills  resulted  in  his  being  received 
into  the  laboratory  of  Professor  du  Bois,  one  of  the  leading  authorities  in 
magnetism,  in  Berlin,  where  he  performed  a  number  of  other  interesting 
pieces  of  research  in  the  same  subject.  Mr.  B.  F.  Sharpe  spent  the 
greater  part  of  three  years  in  developing  a  method  devised  by  the  writer 
for  the  measurement  of  the  intensity  of  sound,  a  measurement  of  more 
than  ordinary  difficulty.  The  instrument  depends  upon  the  application 
of  Michelson's  interference  methods  to  the  measurement  of  the  very  small 


Physics.  95 

distances  involved  in  the  vibration  of  plates  set  in  motion  by  sound. 
The  interference  bands  observed  in  an  interferometer,  of  which  one  mova- 
ble mirror  is  fixed  upon  a  plate  of  thin  glass  forming  the  back  of  a  reso- 
nator, are  observed  through  a  moving  telescope,  or  have  their  motion 
photographically  registered.  In  this  manner  a  very  sensitive  means  of 
measurement  is  obtained,  and  it  is  possible  to  measure  sound  in  absolute 
measure,  even  when  it  is  rapidly  varying  in  intensity,  a  result  not  before 
attainable.  The  applications  of  this  method  which  have  been  already 
suggested  are  very  numerous  and  important. 

Mention  should  not  be  omitted  of  the  labors  of  Mr.  F.  L.  O.  Wads- 
worth,  who,  as  assistant  to  Professor  Michelson,  by  his  untiring  energy 
and  especial  skill  in  the  design  and  construction  of  apparatus,  contributed 
in  large  measure  to  the  success  of  the  researches  of  the  latter. 

The  most  important  experimental  paper  published  by  the  writer  was 
a  determination  of  the  period  of  electrical  oscillations  in  a  circuit  contain- 
ing a  condenser  and  a  coil,  the  purpose  of  the  investigation  being  to 
verify  the  formula  of  Lord  Kelvin,  all  the  constants  of  the  apparatus 
being  measured  in  absolute  measure.  For  the  research  a  new  instru- 
ment was  devised  capable  of  breaking  two  electrical  contacts  at  instants 
separated  by  a  very  small  measured  interval  of  time.  The  instrument 
was  very  sensitive,  permitting  the  appreciation  of  less  than  a  millionth  of 
a  second.  This  research,  already  begun  in  the  attempt  to  improve  a 
method  for  the  determination  of  the  ratio  of  the  two  units  of  electricity, 
was  found  to  correspond  to  a  question  proposed  by  a  committee  in  Paris 
having  in  charge  the  prize  established  by  Elihu  Thomson,  and  being  sub- 
mitted for  the  competition,  was  awarded  the  prize  of  five  thousand 
francs. 

During  the  first  year  of  the  history  of  the  University  a  considerable 
sum  was  spent  upon  a  set  of  meteorological  instruments,  especially  for 
the  study  of  atmospheric  electricity,  and  research  was  begun  in  this 
subject  by  Mr.  Alexander  McAdie,  of  the  Weather  Bureau,  who  has  now 
become  a  recognized  authority  upon  the  subject  of  lightning  discharges. 
This  work  came  to  an  end  upon  the  departure  of  Mr.  McAdie  from  the 
University,  but  it  might  with  advantage  be  resumed,  with  the  addition  of 
observations  of  phenomena  of  terrestrial  magnetism. 

In  concluding  this  report,  it  will  not  be  out  of  place  to  speak  of  the 
needs  and  ideals  of  the  department  for  the  future.  It  is  extremely 
desirable  that  the  courses  in  mathematical  physics  be  repeated  every  year, 


96  Department  of 

instead  of  once  in  two  years  as  at  present,  this  being  as  often  as  the  time 
and  strength  of  a  single  lecturer  will  allow  him  to  cover  the  subject.  If 
this  were  done,  students  could  then  begin  each  year  at  the  most  appropri- 
ate part  of  the  course,  without  waiting  for  the  natural  beginning  in  their 
second  year,  as  is  now  necessary  for  those  students  coming  in  alternate 
years.  Even  more  desirable  than  aid  in  instruction  is  assistance  in 
experimental  work.  Research  in  the  laboratory  can  be  carried  out  much 
more  economically  if  a  number  of  assistants  are  available  to  carry  out 
details,  leaving  the  professor  free  for  the  more  important  work  of 
planning  and  personally  attending  to  the  more  difficult  parts  of  the 
work. 

One  of  the  most  important  adjuncts  of  the  department,  the  workshop, 
in  which  a  skilled  mechanic  is  constantly  employed  in  the  construction  of 
apparatus  for  research,  is  capable  of  great  extension  of  facilities.  The 
absolute  necessity  of  this  work  cannot  be  too  strongly  emphasized,  and 
the  department  could  even  at  the  present  moment  profitably  employ  two 
or  three  men  instead  of  one.  Research  in  physics  demands  instruments 
of  great  exactness,  complication,  and  cost,  so  that  the  maintenance  of 
such  a  department  in  which  research  is  done  entails  more  expense  than 
that  of  any  other  scientific  department,  except  engineering.  Each  partic- 
ular research  requires  much  of  the  apparatus  used  in  it  to  be  particularly 
designed,  so  that  in  view  of  the  frequent  changes  necessitated  before 
it  exactly  fits  its  purpose,  and  of  the  fact  that  it  is  impossible  as  a  rule  to 
find  it  kept  in  stock  by  dealers,  it  is  more  economical  to  have  apparatus 
constructed  in  the  workshop  of  the  department  under  the  eye  of  the 
professor  than  to  have  it  made  elsewhere. 

In  designing  an  ideal  laboratory,  one  of  the  first  things  to  be  con- 
sidered would  accordingly  be  a  workshop  well  equipped  with  modern 
machine  tools,  with  an  ample  and  convenient  source  of  power  for  driving 
them,  and  with  a  large  electric  storage  plant,  both  as  a  source  of  supply 
for  investigations  in  electricity  and  magnetism,  and  for  the  purpose 
of  furnishing  power  in  smaller  quantities  than  would  require  the  main 
supply.  An  optical  shop  would  greatly  increase  the  capability  of  a 
laboratory  for  work  in  light.  That  such  a  suggestion  is  not  extrava- 
gant is  shown  by  the  fact  that  Professor  Michelson's  new  and  ingenious 
echelon  spectroscope  was  constructed  by  methods  devised  by  him  in  the 
workshop  of  his  laboratory,  and  could  not  have  been  so  well  constructed 
anywhere  else.     The  famous  diffraction  gratings  of  Professor  Rowland 


Physics.  97 

have  for  years  furnished  a  further  striking  example,  forcing  European 
physicists  to  send  to  this  country  for  their  supply. 

A  laboratory  should  be  provided  with  the  means  for  the  determina- 
tion of  the  important  physical  constants  of  nature,  such  as  the  velocity 
of  light  and  of  electric  waves,  of  the  Newtonian  constant  of  gravitation, 
of  the  mechanical  equivalent  of  heat,  and  of  the  fundamental  relation 
between  electricity  and  magnetism,  the  so-called  "  v "  of  Maxwell. 
Thus  it  would  be  possible  not  only  to  initiate  students  into  the  most 
precise  methods,  but  even  to  hope  to  improve  upon  classical  determina- 
tions. Ample  facilities  should  be  always  at  hand  for  the  comparison 
and  calibration  of  the  important  physical  standards  of  measurement,  such 
as  those  of  length,  time,  mass,  of  electrical  and  magnetic  quantities. 
The  small  facilities  in  this  line  possessed  even  by  our  national  govern- 
ment are  in  painful  contrast  to  what  is  seen  in  Europe,  particularly  in 
the  German  Imperial  Physico-technical  Institute,  in  which  a  million  or 
more  of  dollars  is  invested. 

Beside  the  matter  of  accurate  measurements  of  well-known  phe- 
nomena lies  the  wider  field  of  research  in  fields  which  are  sure  to  prove 
fertile  in  new  discoveries.  The  great  domain  of  electrical  waves,  a 
creation  of  the  last  decade,  although  already  exploited  by  scores  of 
observers,  is  still  full  of  interesting  problems,  that  are  sure  to  yield  a 
rich  reward  to  those  who  shall  devise  more  perfect  methods  of  investiga- 
tion. The  field  of  spectroscopy,  whether  in  its  terrestrial  or  celestial 
applications,  is  an  enormous  one.  To  this  is  to  be  added  the  study  of 
radiations  in  general,  of  whatever  character.  The  recent  discovery  of 
Rontgen  was  followed  quickly  by  hundreds  of  researches  bearing  on  the 
rays  discovered  by  him,  resulting  in  the  discovery  of  several  closely 
allied  forms  of  radiation,  and  in  a  greatly  increased  interest  in  the 
phenomena  of  electrical  discharges  in  vacuum  tubes.  Here  remain  a 
multitude  of  questions  to  be  decided.  The  nature  of  cathode  and  of 
Rontgen  rays  remains  to  be  settled,  and  will  probably  be  one  of  the 
achievements  of  the  early  years  of  the  next  century.  Research  on  the 
liquefaction  of  gases,  and  on  the  properties  of  bodies  at  temperatures 
not  far  removed  from  the  absolute  zero,  until  recently  limited  to  a  few 
observers  possessing  far  more  than  ordinary  facilities,  will  soon  furnish 
a  field  for  the  labors  of  many,  who  will  undoubtedly  be  well  repaid. 
The  many  relations  predicted  by  the  recent  applications  of  thermody- 
namics, especially  in  the  domain  of  physical  chemistry,  remain  in  large 


98  Deimrtment  of  Physics. 

measure  to  be  verified.  The  science  of  meteorology,  hitherto  largely 
an  empirical  one,  remains  to  be  put  upon  a  satisfactory  theoretical  basis, 
and  presents  many  problems  for  the  physicist  to  attack  in  his  laboratory. 
The  same  may  be  said  of  geology,  which  is,  for  example,  vitally  con- 
cerned with  the  thermal  properties  of  rocks  and  other  materials  of  the 
substance  of  the  earth,  and  with  many  problems  concerning  the  physics 
of  the  earth's  crust. 

The  foregoing  is  but  a  brief  sketch  of  the  field  of  physical  investiga- 
tion. The  enthusiasm  of  one  devoted  to  the  performance  of  research, 
and  considering  it  the  most  attractive  form  of  human  endeavor,  would 
enable  him  to  enlarge  the  subject  over  many  more  pages  than  are  here 
available.  The  field  is  enormous,  and  each  new  discovery  leads  to  new 
paths  of  inquiry.  It  is  obvious  that,  in  order  to  enter  upon  these 
attractive  fields  of  work,  one  must  be  provided  with  large  resources. 
Is  it  unreasonable  to  look  forward  eagerly  to  the  day  when  Clark 
University  shall  possess  a  well-equipped  physical  laboratory  building, 
fitted  out  with  the  utmost  that  our  knowledge  can  suggest,  in  which 
we  may  hope  to  contribute  our  just  share  toward  the  enlargement  of 
the  boundaries  of  science,  and  thus  to  the  welfare  of  humanity? 


DEPAKTMENT   OF   BIOLOGY. 

By  Clifton  F.  Hodge. 

PAST  AND  PRESENT  STAFF. 

Charles  0.  Whitman,  Ph.D.,  Professor  of  Animal  Morphology,  1889-92. 

Franklin  P.  Mall,  M.D.,  Adjunct  Professor  of  Anatomy,  1889-92. 

Henry  H.  Donaldson,  Ph.D.,  Assistant  Professor  of  Neurology,  1889-92. 

Warren  P.  Lombard,  M.D.,  Assistant  Professor  of  Physiology,  1889-92. 

Clifton  F.  Hodge,  Ph.D.,  Assistant  and  Fellow  in  Neurology,  1889-91 ; 
Assistant  Professor  of  Physiology  and  Neurology,  1892-. 

J.  P.  McMuRRiCH,  Ph.D.,  Docent  in  Morphology,  1889-91;  Assistant  Pro- 
fessor of  Morphology,  1891-92. 

Adolf  Meyer,  M.D.,  Docent  in  Psychiatry,  1895-. 

fGEORGE  Baur,  Ph.D.,  Docent  in  Comparative  Osteology  and  Paleontology, 
1890-92.     Died  June  25,  1898. 

John  C.  Cardwell,  M.D.,  Assistant  in  Physiology,  1889-91. 

Sho  Watase,  Ph.D.,  Lecturer  and  Assistant  in  Morphology,  1890-92. 

FELLOWS  AND  SCHOLARS. 

Franklin  W.  Barrows,  M.D.,  Fellow  in  Physiology,  1893-94. 
Charles  L.  Bristol,  Fellow  in  Morphology,  1891-92. 
Hermon  C.  Bumpus,  Fellow  in  Biology,  1889-90. 
Albert  C.  Eycleshymer,  Fellow  in  Morphology,  1891-92. 
Charles  L.  Edwards,   Ph.D.,  Fellow  in  Morphology,  1890-92. 

E.  R.  GuRLEY,  M.D.,  Fellow  in  Biology,  1895-96. 

Homer  Gage,  M.D.,  Honorary  Scholar  in  Anatomy,  1889-90. 
Edwin  0.  Jordan,  Fellow  in  Morphology,  1890-92. 
Herbert  P.  Johnson,  Fellow  in  Morphology,  1891-92. 

F.  C.  Kenyon,  Ph.D.,  Fellow  in  Biology,  1895-96. 

tW.  E.  Lockwood,  M.D.,  Fellow  in  Physiology,  1891-92.     Died  June  23,  1897. 

Frank  E.  Lillie,  Fellow  in  Morphology,  1891-92. 

A.  D.  Mead,  Fellow  in  Morphology,  1891-92. 

William  S.  Miller,  M.D.,  Honorary  Scholar,  1889-90;  Scholar  in  Anatomy, 

1890-91 ;  Fellow  in  Anatomy,  1891-92. 
James  E.  Slonaker,  Fellow  in  Biology,  1893-96. 


100  Department  of 

Colin  C.  Stewart,  Scholar  in  Physiology,  1894-95 ;   Fellow  in  Physiology, 

1895-97. 
Frederick  Tuckerman,  M.D.,  Ph.D.,  Fellow  in  Anatomy,  1889-90, 
William  M.  Wheeler,  Fellow  in  Morphology,  1890-91 ;  Assistant,  1891-92. 


SPECIAL   STUDENTS. 

James  Jenkixs,  Special  Student  in  Biology,  1894-95. 
Preston  Smith,  Special  Student  in  Physiology,  1899. 
W.  G.  Watts,  Laboratory  Steward  and  Special  Student,  1889-91. 


HISTORICAL  REVIEW. 


It  will  be  seen  from  the  above  list  of  appointments  that  the  depart- 
ment was  organized  to  cover  animal  biology.  Animal  morphology,  ver- 
tebrate anatomy,  physiology,  comparative  osteology  and  paleontology,  and 
neurology,  which  forms  the  natural  transition  to  psychology,  and  has 
been  classed  in  that  department,  formed  a  compact  and  well-selected 
group  with  which  to  begin  work.  This  organization  was  still  further 
strengthened  by  a  strong  force  of  organic  chemists  in  this  fundamental 
department. 

A  good  share  of  the  equipment  necessary  for  different  lines  of  research 
work  already  in  progress  or  planned  by  the  different  appointees  had  been 
ordered  during  the  previous  summer,  so  that  the  work  of  the  whole 
department  began  practically  with  the  opening  of  the  University.  Zeiss 
microscopes  of  the  most  approved  patterns  and  with  full  complements  of 
apochromatic  eye-pieces  and  objectives,  Thoma  microtomes,  together  with 
those  of  Minot,  the  Minot-Zimmerman,  Schanze,  and  others,  complete  assort- 
ments of  chemical  reagents,  stains  and  laboratory  tools,  apparatus  and 
glassware,  all  were  supplied  with  liberality.  Abundant  and  suitable 
rooms  were  also  placed  at  the  department's  disposal  in  the  main  univer- 
sity building.  Two  large  rooms  and  a  convenient  dark  room  for  photo- 
graphic purposes  on  the  fourth  floor  were  assigned  to  physiology  and 
were  devoted  to  laboratory  and  lecture-room  with  w^orkshop  equipped  with 
lathe  and  tools  for  working  both  wood  and  metals.  Four  large  rooms  on  the 
third  floor  were  arranged  to  accommodate  anatomy  and  morphology  for 
laboratories,  lecture-room  and  drafting  room  ;  and,  in  addition,  four  small 
rooms  adjoining  supplied  office  and  library  for  the  head  of  the  depart- 


Biology.  101 

ment,  and  private  laboratories  for  three  of  the  docents  and  assistants. 
Two  rooms  on  the  second  floor,  adjoining  the  psychological  department, 
were  assigned  to  neurology,  the  one  for  private  laboratory  and  office  of 
Assistant  Professor  Donaldson,  the  other  for  his  general  laboratory.  All 
of  these  rooms  were  equipped  with  water  and  gas,  and  some  with  hoods  to 
render  them  the  most  convenient  and  ideal  laboratories  possible,  and  the 
morphological  laboratories  were  furnished  with  five  large  aquaria,  the 
largest  being  eight  feet  in  length,  all  supplied  with  running  water,  and  a 
large  number  of  smaller  glass  aquaria  which  made  it  possible  to  keep  all 
sorts  of  aquatic  animals  both  summer  and  winter. 

While  the  chief  emphasis  both  as  to  equipment  and  disposition  of  the 
instructor's  time  was  given  to  research,  the  side  of  instruction  toward 
breadth  and  depth  of  view,  so  necessary  to  the  highest  type  of  investiga- 
tion, was  not  neglected.  Models  of  the  brain  (Auzoux,  Aeby,  Ziegler), 
as  well  as  Ziegler 's  models  of  classic  embryological  types,  and  a  complete 
set  of  Leuckart  &  Nitche's  zoological  charts,  and  an  extensive  library 
of  wall  charts  copied  from  various  monographs  and  text-books,  all 
these,  supplemented  by  anatomical  and  zoological  specimens,  gathered 
as  rapidly  as  possible  to  form  the  nucleus  of  a  museum,  imparted  the 
best  possible  quality  to  the  work  of  instruction.  In  fact,  instruction 
and  research  began  together  and  went  hand  in  hand,  the  one  aiding  the 
other. 

Professor  Whitman  immediately  began  courses  of  lectures  funda- 
mental to  the  doctrine  of  evolution.  The  first  of  these  treated, 
entirely  from  original  sources,  the  historical  development  of  Compara- 
tive Anatomy,  beginning  with  its  renaissance  in  the  works  of  Marco 
Aurelio  Severino  ("  Zootomia  Democritsea,  id  est  Anatome  generalis  totius 
animalium  opificii  libris  quinque  distincta,"  1645),  and  bringing  the  sub- 
ject down  to  the  discussions,  just  preceding  the  Darwinian  epoch, 
between  Etienne  Geoffroy  Saint  Hilaire  and  Georges  Cuvier  (1830). 
As  Professor  Whitman  himself  announced  with  reference  to  this  early 
course  :  "  Attention  will  be  directed  particularly  to  the  origin  and 
development  of  historic  ideas,  tendencies,  methods,  and  schools,  as  pre- 
sented in  the  early  iatric  and  physiological  stages  of  Zootomy ;  in  the 
works  of  Haller,  Geoffroy,  and  Cuvier ;  in  the  '  Anatomic  Philosophique ' 
of  the  French,  and  the  '  Naturphilosophie '  of  the  Germans  ;  in  the 
doctrines  of  the  '  Scale  of  Nature,'  '  Unity  of  Composition,'  and  of 
'  Types '  ;  in  the  hypotheses  of  Evolution  and  Epigenesis,  in  Homology 


102  Deioartment  of 

and  Teleology,  etc.  The  biographical  side  of  the  subject  will  also 
receive  due  consideration,  especially  in  the  cases  of  such  representa- 
tive men  as  Malpighi,  Swammerdam,  and  Leeuwenhoek  of  the  seven- 
teenth century,  and  Haller,  Buffon,  Daubenton,  Linn^,  John  Hunter, 
Camper,  Vicq-d'Azyr,  Kielmeyer,  Geoffroy,  and  Cuvier  of  the  later 
period." 

A  second  and  third  historical  course  was  devoted  respectively  to  the 
subjects  of  Generation  and  Comparative  Embryology.  These  courses, 
compactly  coordinated,  and  following  logically  on  the  development  of 
comparative  anatomy,  were  likewise  worked  up  from  original  sources 
in  Aristotle,  Harvey,  John  Hunter,  Wolff,  Von  Baer,  and  others,  and 
led  naturally  up  to  the  modern  doctrines  of  heredity  as  developed  by 
Lamarck,  Darwin,  Weismann,  and  their  followers.  Especially  in  the 
course  in  Comparative  Embryology,  the  present  phase  of  biological  work, 
cytological  technique  and  terminology,  were  fully  treated,  together  with 
matters  of  interest  in  recent  discussions  as  to  origin  and  maturation 
of  ova  and  spermatozoa,  phenomena  of  fecundation,  cleavage  of  the 
o\Tim,  with  comparison  of  different  types  of  cleavage  and  experimental 
researches  in  cleavage,  gastrular  and  pre-gastrular  stages,  their  differ- 
ent types  and  derivations,  germ  layers,  the  trochosphere,  budding  and 
fission,  formation  of  the  embryo  in  invertebrates  and  vertebrates,  to- 
gether with  that  of  double  and  multiple  monsters,  and,  finally,  the 
course  culminated  in  a  discussion  of  the  origin  and  significance  of 
metameric  segmentation. 

Simultaneously  with  these  courses  Dr.  McMurrich  lectured  on  the 
coelenterates  and  platyhelminths,  sifting  all  discoverable  evidences  for 
coelenterate  ancestry  of  the  worms,  the  origin  of  segmentation,  and 
the  significance  of  ccelenterate  structure  in  gastrular  stages  of  vertebrate 
embryos.  Dr.  Baur  on  the  side  of  paleontology  discussed  the  osteology 
of  reptiles  and  mammals,  living  and  extinct.  Dr.  Bumpus  also  lectured 
on  the  affinities  of  the  Crustacea. 

For  two  years,  as  a  means  of  uniting  still  further  instruction  and 
research,  and  of  keeping  all  members  of  the  department  in  touch  with 
one  another,  an  active  biological  club  was  maintained.  Monthly  meet- 
ings were  held,  and  at  each  a  carefully  prepared  lecture  was  read  and 
discussed.  The  subjects  of  these  lectures  indicate  to  such  an  extent 
the  lines  of  interest  developed  in  the  department,  that  a  list  for  1890- 
92  is  given  in  full. 


Biology.  103 

1.  Scope  and  Aims  of  the  Club.  —  C.  0.  Whitman. 

2.  Ideas  on  the  Origin  of  the  Galapagos  Islands  and  the  Origin  of  Species. 

—  Geo.  Baur. 

3.  Insect  Metamorphosis.  —  W.  M.  Wheeler. 

4.  The  Origin  and  Significance  of  the  Blastopore.  —  J.  P.  McMurrich. 

5.  Nitrification  and  Nitrifying  Organisms.  —  E.  0.  Jordan. 

6.  The  Animal  Ovum.  —  Sho  Watase. 

1.  The  Salisbury  Expedition  to  the  Galapagos  Islands.  —  Geo.  Baur. 

2.  The  Third  Eye  of  Vertebrates.  —  A.  C.  Eycleshymer. 

3.  Some  Points  in  the  History  of  Bacteriology.  —  E.  0.  Jordan. 

4.  Amphimixia  in  the  Protozoa.  —  H.  P.  Johnson. 

5.  Nervous  System  of  Mollusca.  —  F.  R.  Lillie. 

6.  Germ  Cells.  —  Sho  Watase. 

7.  Mammalian  Spermatogenesis.  —  Sho  Watase. 

8.  Metamerism  in  Arthropods.  —  W.  M.  Wheeler. 

The  scope  of  work  of  the  morphological  section  will  be  seen  more 
fully  in  the  list  of  investigations  which  follows,  under  the  heading  of 
Research  Work,  which  has  been  grouped  together  for  all  divisions  of  the 
biological  department. 

In  Vertebrate  Anatomy,  Dr.  Mall  lectured  for  three  successive  years 
on  the  histology  of  tissues  arising  from  the  mesoderm,  on  the  develop- 
ment of  serous  and  blood  spaces  in  vertebrates,  and  on  the  development, 
histology,  and  comparative  anatomy  of  the  organs  arising  from  the 
endoderm.  Dr.  Tuckerman  lectured  in  connection  with  his  research 
work,  on  the  gustatory  organs  of  mammals,  and  Dr.  Miller  likewise  on 
the  lobule  of  the  lung  with  its  blood-vessels. 

In  Physiology  Dr.  Lombard  devoted  a  series  of  lectures  of  a  year 
each,  supplemented  by  numerous  demonstrations,  to  the  following  sub- 
jects :  — 

1.  Physiology  of  Muscle  and  Nerve. 

2.  Physiology  of  Circulation  and  Respiration  and  the  Nervous  Mechanisms 
by  which  they  are  regulated. 

3.  Physiology  of  Muscle,  Nerve,  and  Spinal  Cord. 

Dr.  Cardwell  gave  a  number  of  lectures  upon  Animal  Locomotion 
and  Coordination.  And  Drs.  Hodge  and  Jordan  lectured  respectively 
on  the  Physiology  of  Spinal  and  Peripheral  Ganglia,  and  the  Physiology 
of  Leucocytes. 


104  Department  of 

A  convenient  laboratory  was  fitted  up  with  microscopes,  microtomes, 
and  all  needed  instruments,  materials,  and  reagents  for  neurology.  A 
number  of  brain  and  other  neurological  specimens  were  prepared  for 
purposes  of  instruction  and  demonstration,  and  the  best  neurological 
models  were  purchased  with  this  end  in  view. 

Dr.  Donaldson  lectured  during  1889-90  on  the  anatomy  of  the  central 
nervous  system  in  man  ;  and  in  1890-91  completed  the  course  by  treat- 
ing the  peripheral  nervous  system  and  discussing  at  length  the  various 
physical  measures,  so-called,  of  intelligence  as  found  in  the  brain,  its  size, 
weight,  convolution,  thickness  of  cortex,  and  relative  development  of 
lobes,  as  these  have  been  presented  in  the  history  of  neurology.  The 
course  was  repeated  in  1891-92,  together  with  a  practice  course  in  the 
laboratory  on  the  histology  of  the  nervous  system. 

A  seminary  which  met  once  a  week  was  devoted  to  the  reading  of 
papers  on  neurological  topics,  both  of  historical  and  current  interest,  and 
to  reports  on  work  in  progress  in  the  laboratory. 

The  primary  aim  of  the  department,  as  Professor  Whitman  expressed 
it,  is  to  make  "  research  men,"  men  imbued  with  the  spirit  and  desire  for 
original  investigation.  This  purpose  is  seen  in  all  the  courses  of  instruc- 
tion and  becomes  even  more  patent  in  the  number  of  investigations  actually 
in  progress  in  the  different  laboratories  of  the  department.  In  fact,  the 
serious  work  of  every  member  was  research,  for  which  lecture  and  semi- 
nary combined  to  form  an  appropriate  historical  and  philosophical  back- 
ground. 

During  this  period.  Professor  Whitman  being  in  charge  of  Woods 
Holl  Marine  Laboratory,  practically  all  the  men  in  morphology  continued 
their  studies  there  through  the  summer  seasons,  taking  microscopes, 
apparatus,  and  reagents  from  the  University.  Lectures  were  also  given  at 
Woods  Holl  by  Professors  Donaldson,  Lombard,  and  McMurrich,  and 
Drs.  Watase,  Wheeler,  and  Jordan  assisted  Professor  Whitman  with 
the  laboratory  instruction. 

The  following  resume  is  given  to  present  a  general  picture  of  the 
spirit  and  scope  of  the  department's  work  during  this  three-year  period. 

RESEARCH  WORK. 

Professor  Whitman,  in  addition  to  editing  the  Journal  of  Morphology^ 
equipping   and  directing  a  new  and  complicated  laboratory,  and  giving 


Biology.  105 

regular  lectures,  spent  most  of  his  time  investigating  the  Hirudinea, 
publishing  a  series  of  papers  on  their  classification,  with  descriptions  of 
new  species,  on  their  metamerism,  and  on  their  hypodermic  impregnation 
by  means  of  spermatophores.  "  Specialization  and  Organization,"  "  The 
Naturalist's  Occupation,"  and  other  papers  show  that  he  was  following  lines 
of  more  general  interest  both  in  scientific  work  and  in  public  education. 

Dr.  Baur  was  delving  in  problems  of  fundamental  importance  in  com- 
parative osteology  of  vertebrates,  morphology  of  the  vertebrate  skull, 
carpus,  ribs,  etc.,  and  working  out  the  descriptions  of  a  number  of  forms 
discovered  during  his  successful  paleontological  expeditions.  A  good 
share  of  his  work  grouped  itself  about  the  plan  of  his  great  expedition  to 
the  Galapagos  Islands,  which  was  finally  made  possible  by  the  munificence 
of  the  Hon.  Stephen  Salisbury,  together  with  contributions  from  Pro- 
fessor H.  F.  Osbourn  and  from  the  Elizabeth  Thompson  Science  Fund. 
This  trip  Dr.  Baur  made  (in  company  with  Mr.  C.  F.  Adams)  be- 
tween May  and  October  of  1890,  visiting  all  the  islands,  excepting  Nar- 
borough,  Wenman,  and  Culypepper.  Extensive  collections  of  both  flora 
and  fauna  were  obtained,  which  were  worked  up  by  Dr.  Baur  himself  and 
by  specialists  both  in  this  country  and  in  Europe.  The  main  general 
result  of  the  expedition  was  a  demonstration  of  the  fact  that  the  life  on 
these  islands  is  harmonious,  and  hence  that  the  islands  themselves  must  be 
explained  on  the  subsidence  theory,  rather  than  on  that  of  emergence  as 
held  by  Darwin,  Wallace,  and  others. 

Dr.  McMurrich  devoted  his  time  chiefly  to  investigating  the  morphol- 
ogy and  embryology  of  the  Actinozoa,  and  from  these  researches  derived 
his  conclusions  as  to  the  phylogeny  of  the  group.  Dr.  Watase  was  at  work 
on  various  fundamental  problems  on  the  cell,  caryokinesis,  cleavage  of  the 
ovum,  spermatogenesis,  and  sex  differentiation. 

The  research  work  of  other  members  of  the  department  was  dis- 
tributed as  follows  :  Mr.  Johnson  investigated  the  morphology  and 
biology  of  the  Stentor.  Mr.  Lillie  studied  the  embryology  of  Unio.  Dr. 
Wheeler  worked  upon  the  embryology  of  the  Insecta,  and  in  that  connec- 
tion investigated  the  neuroblasts  in  the  Arthropod  embryo.  Dr.  Bumpus 
completed  his  study,  already  under  way,  upon  the  embryology  of  the 
American  lobster.  Dr.  Edwards  studied  the  embryology  of  the  Holo- 
thurians.  Dr.  Jordan  studied  the  life  history  and  embryology  of  the 
common  newt ;  and  Mr.  Eycleshymer  made  a  special  investigation  of  the 
development  of  the  optic  vesicle  in  the  amphibian  embryo. 


106  Department  of 

In  the  closely  allied  field  of  vertebrate  anatomy,  Dr.  Mall  was  making 
a  minute  study  of  a  human  embryo,  investigating  the  formation  of  the 
lesser  peritoneal  cavity  in  birds  and  mammals,  the  motor  nerves  of 
the  portal  vein,  and  also  completed  his  important  work  on  a  new  connec- 
tive tissue  element,  the  reticulated  connective  tissue,  with  its  distribu- 
tion in  the  body.  Dr.  Tuckerman  carried  on  an  extended  research  on 
the  gustatory  organs  of  a  series  of  animals,  and  their  development  in  man. 
Dr.  Miller  also  worked  out  the  minute  anatomy  of  the  lung,  and  by  a  most 
exhaustive  and  varied  method  succeeded  in  demonstrating  for  the  first  time 
the  manner  of  ending  of  the  terminal  bronchi,  together  with  their  relations 
to  the  arteries,  veins,  and  capillary  system.  On  the  side  of  practical  surgery 
Dr.  Homer  Gage  conducted  a  series  of  experiments  on  intestinal  suture. 

In  physiology  Dr.  Lombard  continued  his  investigations  on  effect 
of  fatigue  on  voluntary  muscular  contractions  and  alterations  in  strength 
which  occur  in  severe  muscular  work,  and  on  the  conditions,  barometric 
pressure,  temperature,  sleep,  food,  alcohol,  and  tobacco,  which  effect 
voluntary  effort.  Dr.  Cardwell  investigated  the  physiology  of  the 
cerebellum  with  relation  to  animal  locomotion  and  coordination. 

For  neurology  Dr.  Donaldson  was  pursuing  a  similar  plan  with  that 
followed  by  Dr.  Whitman  in  morphology,  viz.,  gathering  the  history  of 
the  science  from  original  sources,  and  reducing  to  uniform  statements, 
tables,  and  curves  all  the  data  as  to  size  and  weight,  both  relative  and 
absolute,  of  the  brain.  In  this  connection  he  made  an  exhaustive 
study,  both  gross  and  microscopical,  of  the  brain  of  Laura  Bridgman. 
An  extended  series  of  observations  was  also  being  carried  on  in  the 
laboratory  upon  the  influence  of  hardening  reagents  upon  brain  weight 
and  specific  gravity.  Dr.  Hodge  worked  for  two  years  (1889-91) 
on  the  physiology  of  nerve  cells,  their  diurnal  fatigue  and  recovery  in 
sleep,  and  their  recovery  from  effects  of  electrical  stimulation.  Dr. 
Donaldson,  with  Dr.  Bolton,  completed  a  study  of  the  size  of  the  cranial 
nerves  in  man,  and  Dr.  Bolton  studied  microscopically  the  spinal  cord 
of  a  horse  affected  with  spring  halt. 

The  above  gives,  in  the  main,  a  picture  of  the  work  in  progress 
during  the  first  three  years  of  the  department's  existence.  All  but 
one  or  two  of  the  researches  mentioned  have  been  published,  together 
with  others  not  cited.  For  place  of  publication  and  the  complete  record 
the  reader  is  referred  to  list  of  publications  by  members  of  the  University 
for  the  corresponding  years. 


Biology.  107 

If  one  science  is  entitled  to  claim  the  special  interest  of  the  founder 
more  than  another,  biology  is  that  science ;  and  in  the  organization  of  this 
department,  the  aim  above  all  else  was  to  make  it  the  most  ideal  pos- 
sible place  for  biological  research.  Foundations  were  laid  at  this  time 
for  a  special  building  more  adequately  to  house  this  flourishing  depart- 
ment. How  well  the  ideal  was  realized  may  be  seen  from  the  estimate 
of  Professor  Whitman,  whose  experience  in  the  laboratories  of  three 
continents  entitles  him  to  an  opinion.  Writing  in  1899,  he  says,  "  The 
Clark  University  Ideal,  as  I  understood  it  when  connected  with  its  early 
work,  is  the  ideal  which  I  place  above  any  other  thus  far  proposed,  and 
I  hope  it  may  find  strong  friends  to  help  it  forward."  Unencumbered 
by  the  burden  of  undergraduate  courses,  untrammelled  by  red  tape  and 
traditions,  the  laboratory  formed  for  three  brief  years  a  veritable  garden 
spot  in  the  field  of  biological  history  in  this  country.  It  was  a  place 
where  each  man  was  free  to  devote  all  his  best  energies  to  just  that 
which  he  wanted  most  to  discover ;  where  the  best  thing  a  man  could 
possibly  do  for  himself  constituted  the  highest  service  he  could  render 
to  the  University. 

A  "Flying  Squadron,"  has  been  suggested  as  the  most  fitting  defi- 
nition for  a  university.  Scarcely  had  this  splendid  organization  been 
attained  than  it  was  carried  off  bodily,  almost,  to  lay  foundations  for  the 
biological  department  in  a  new  university.  While  no  higher  tribute 
could  have  been  paid  to  Clark  University,  it  has  left  the  department 
sadly  crippled  both  for  men  and  means  for  work. 

Since  1892  biology  has  been  represented  by  but  a  single  instructor. 
Dr.  Hodge,  who  was  recalled  from  the  University  of  Wisconsin,  with 
the  title  of  Assistant  Professor  of  Physiology  and  Neurology.  For  the 
first  year  Dr.  Hodge  offered  only  courses  on  the  physiology,  anatomy, 
and  embryology  of  the  nervous  system.  During  the  succeeding  years, 
owing  to  the  great  need  of  having  the  subject  pl-esented,  a  course  in  gen- 
eral biology  has  been  given,  the  aim  of  which  is  to  present  the  funda- 
mental principles  of  the  science.  A  sense  of  the  importance  of  this 
course  has  grown  from  year  to  year,  with  the  conviction  that  the  sub- 
ject finds  too  little  representation  in  most  of  our  educational  institutions  ; 
and  it  is  hoped,  as  soon  as  practicable,  to  develop  it  into  a  solid  course, 
historical,  philosophical,  and  practical,  to  extend  through  all  of  two  and 
possibly  three  years  of  university  study.  The  main  courses  offered  by 
Dr.  Hodge  have  related  to  anatomy  and  physiology  of  the  nervous  sys- 


108  Departme7it  of 

tern,  both  comparative  and  human,  including  the  sense  organs  as  well, 
and  to  the  entire  field  of  physiology  and  to  that  of  embryology,  especially 
of  the  nervous  system  and  sense  organs.  These  have  been  supplemented, 
wherever  possible,  by  laboratory  courses.  A  seminary  meeting,  usually 
one  evening  weekly,  has  been  maintained,  the  plan  of  which  has  been, 
in  the  main,  to  spend  a  year  upon  each  of  the  three  following  top- 
ics :  1,  history  of  medicine,  with  special  reference  to  physiology,  epochs, 
schools,  and  men  ;  2,  history  of,  and  present  discussion  centring  about,  the 
doctrine  of  evolution ;  3,  development  of  neurology.  A  journal  club, 
meeting  weekly,  has  aided  to  bring  all  members  of  the  department 
together  for  discussion  of  articles  in  current  literature.  In  general,  all 
seminaries  and  courses  of  instruction  have  been  given  with  reference  to 
furnishing  aid  and  stimulus  to  students  in  their  research  work. 

In  addition  to  the  above,  on  the  teaching  side.  Dr.  Hodge  has 
become  interested  in  lines,  especially  of  biological  education  in  ele- 
mentary schools.  A  definite  standpoint  for  elementary  nature  study  has 
been  developed,  which  is  a  distinct  reaction  against  the  tendency  toward 
technicality,  classification,  and  minutiae  which  have  come  to  constitute  so 
large  a  part  of  our  elementary  science  courses.  It  is  planned  to  include 
this  in  the  general  biology  course  by  way  of  discussing  the  question. 
What  aspects  of  biological  science  shall  be  taught  in  the  elementary 
school  ?  The  kind  of  physiology  which  should  form  a  part  of  elementary 
education  has  also  been  given  considerable  attention.  Both  subjects  have 
formed  the  basis  for  courses  in  the  summer  school. 

In  passing  to  consider  the  research  work  of  the  department  since  Dr. 
Hodge  took  charge  of  it,  a  word  as  to  its  general  purpose  and  plan  will 
simplify  the  discussion. 

Science,  in  this  country  especially,  has  become  unnecessarily  arrogant. 
We  hear  on  all  sides  such  expressions  as  "  pure  science,"  a  term  which 
Huxley  wished  had  never  been  invented,  "  truth  for  truth's  sake  "  or 
"  science  for  the  sake  of  science,"  and  the  "  uselessness  "  of  science  is 
made  a  boast.  An  important  truth  is  stated  in  these  expressions  ;  for 
science  is  of  such  paramount  use  and  importance  to  mankind  that  to 
discuss  this  point  with  one  who  says  it  is  not,  is  clearly  "  casting  pearls 
before  swine."  Possibly  another  reason  for  resorting  to  these  expres- 
sions is  that  the  human  values  attaching  to  knowledge  are  so  enor- 
mous that  we  have  no  measures  or  terms  with  which  to  adequately 
express   them.      However   this   may  be,  if  science  have  a  faith  worthy 


Biology.  109 

of  respect,  it  should  result  in  mutual  benefit  to  share  it  so  far  as  pos- 
sible with  a  reasonable  and  intelligent  public. 

A  research  laboratory  is  an  institution  the  business  of  which  is  to 
investigate  those  problems  which  have  either  never  been  attempted  or 
have  hitherto  baffled  all  efforts  of  the  human  mind  to  solve.  These 
problems  are  not  far  to  seek,  but  crowd  upon  our  lives  at  every  point. 
The  values  attaching  to  their  solutions  can  be  expressed  only  in  terms  of 
human  life  and  happiness,  compared  with  which  the  output  of  Klondikes 
and  Cripple  Creeks  is  but  the  small  change  of  the  hour.  It  is  clearly 
recognized  that  we  may  not  be  able  to  estimate  the  value  of  truth  until  it 
be  discovered,  and  that  the  investigator  himself,  who  is  willing  to  devote 
his  time  and  energies  to  the  work,  should  be  the  one  to  estimate  its  values, 
and  that  he  should  have  the  greatest  freedom  to  select  the  task  for  which 
he  knows  himself  to  be  best  fitted.  Still,  one  must  be  a  man  before  he 
can  be  a  scientist,  and  fundamental  human  values  must  be  in  the  main 
the  same  for  all.  And  it  would  seem  to  be  the  first  duty  of  a  research 
laboratory  to  devote  its  resources  to  the  work  of  solving  those  problems 
which  concern  human  life  most  closely,  and  possess  the  greatest  human 
importance.  A  laboratory  owes  no  less  than  this  to  a  community  ;  or, 
better  stated,  a  laboratory  is  that  part  or  organ  of  a  community  differ- 
entiated to  perform  the  special  function  of  discovering  and  making  avail- 
able whatever  truth  is  of  greatest  value  to  its  common  life. 

In  deciding  the  directions,  therefore,  which  research  work  shall  take, 
the  above  general  policy  has  been  followed,  and  it  is  a  satisfaction  to  note 
that  the  same  sentiment  was  prominently  expressed  at  the  founding  of 
the  University.     On  that  occasion  Mr.  Hoar  spoke  as  follows  :  — 

"  Speaking  now  for  myself  alone,  I  have  little  sympathy  with  that  arrogant 
and  disdainful  spirit  with  which  some  men  who  undertake,  with  little  title,  to 
represent  science  in  this  country,  sneer  at  any  attempt  to  make  use  of  the 
forces  she  reveals  to  us  for  the  service  of  mankind.  Some  one  said  the  other 
day  that  science  was  becoming  a  'hod-carrier.'  I  do  not  see  why  the  term 
'  hod-carrier '  should  express  the  relation  rather  than  the  term  '  benefactress.' 
I  do  not  see,  either,  that  there  is  anything  degrading  in  the  thought  that 
the  knowledge  of  the  learned  man  enables  him  to  lift  the  burden  beneath  which 
humanity  is  bowed  and  bent.  I  do  not  know  that  science  is  exempt  from  the 
divine  law,  '  He  that  is  greatest  among  you,  let  him  be  the  servant  of  all.'  If 
the  great  forces  of  the  universe  perform  all  useful  offices  for  man,  if  the  sun- 
shine warm  and  light  our  dwellings,  if  gravitation  move  the  world  and  keep  it 
true  to  its  hour,  nay,  if  it  keep  the  temple  or  cathedral  in  its  place  when  the 


110  Department  of 

hod-carrier  has  builded  it,  I  do  not  see  why  it  should  not  lend  its  beneficent  aid 
to  him  also.  Our  illustrious  philosopher  advised  his  countryman  to  "  hitch  his 
wagon  to  a  star."  The  star  will  move  no  less  serenely  on  its  sublime  pathway 
when  the  wagon  is  hitched  to  it.  I  do  not  know  that  any  archangel  or  god- 
dess, however  resplendent  the  wings,  has  ever  yet  been  constructed  or  imag- 
ined without  feet.  I  do  not  know  that  any  archangel,  however  glorious,  has 
ever  been  created  or  imagined  without  sympathy  for  suffering  humanity. 

"  I  look  for  great  advantage  to  the  country,  both  in  wealth  and  power  and 
in  the  comfort  and  moral  improvement  of  the  people,  by  the  application  of 
science  to  the  useful  arts." 

The  maimer  in  which  this  fundamental  purpose  has  been  carried  out 
thus  far  may  now  be  seen  in  part  in  the  lines  of  work  which  have  been 
carried  out,  and,  more  fully,  in  plans  for  the  future. 

In  this  country  of,  so-called,  nervous  tension,  nervousness  and  nervous 
prostration,  nothing  could  be  of  greater  value  to  the  common  life  than 
knowledge  of  the  fundamental  laws  of  the  working  of  nerve  protoplasm. 
It  is  only  in  discovery  and  obedience  to  these  laws  that  we  may  hope  for 
escape  from  present  evils  and  possession  of  sane  and  permanent  national 
health.  Consequently  lines  of  investigation  upon  the  physiology  of 
the  nerve  cell  have  been  kept  open  from  the  beginning.  Continuing  the 
studies  mentioned  in  speaking  of  an  earlier  period  in  the  history  of  the 
laboratory,  the  nerve  cell  has  been  studied  during  its  electrical  stimulation 
.and  also  in  connection  with  changes  which  occur  in  the  process  of  aging 
and  in  death  from  old  age.  Dr.  Barrows  has  investigated  its  appearance 
nnder  various  kinds  of  diet  and  when  the  body  has  been  deprived  of  food, 
Dr.  Stewart  has  studied  the  effect  of  alcohol  on  the  cells  of  the  cerebrum, 
cerebellum,  and  spinal  cord.  Drs.  Starbuck  and  Lancaster  respectively 
studied  effects  on  the  nerve  cell  of  artificial  (by  means  of  electrical  stimu- 
lation) and  natural  fatigue  carried  to  an  extreme  degree.  Dr.  Kenyon 
devoted  a  year  to  a  most  successful  study  of  the  brain  of  the  honey-bee. 
Dr.  Burk  devoted  considerable  time  in  working  out  the  meduUation  of 
the  brain  in  puppies.  Dr.  Goddard  tested  by  especially  rapid  methods 
of  preparation  theories  as  to  the  possible  amoeboid  movements  of  nerve 
cells  in  conditions  of  activity  and  sleep.  Further  experiments  are  now  in 
progress  on  the  influence  of  alcohol,  and  work  has  been  begun  on  the 
effect  of  other  chemical  substances,  notably  strychnine,  morphine,  and 
nicotine  on  nerve  cells.  For  the  purpose  of  making  possible  a  more  prac- 
tical study  of  the  human  brain,  a  brain  microtome  has  been  devised  in  the 
laboratory  by  Dr.  Goddard,  with  suggestions  from  Dr.   Hodge.      This 


Biology.  Ill 

instrument  is  constructed  on  principles  new  to  such  microtomes  thus  far 
made,  and  has  rendered  it  possible  to  cut  sections  of  the  entire  human 
brain  in  any  desired  plane  with  the  ease  and  uniformity  with  which  smaller 
sections  are  cut  by  the  ordinary  microtomes.  The  blade  of  this  microtome 
was  made,  and  presented  to  the  University,  by  the  firm  of  Loring,  Goes,  & 
Co.  of  Worcester. 

A  research  less  closely  connected  with  the  general  plan,  but  still  es- 
sentially upon  the  nervous  system,  was  carried  out  by  Dr.  Slonaker  upon 
the  eyes  of  vertebrates. 

This  line  of  work  in  the  physiology  of  the  nervous  system  is  one 
which  the  department  proposes  to  continue,  as  opportunities  and  properly 
prepared  men  present  themselves,  until,  it  is  hoped,  the  American  public 
may  be  able  to  live  on  more  amicable  terms  with  its  "nerves." 

In  order  to  attack,  in  a  more  fundamental  manner,  problems  centring 
about  the  nerve  cell  and  its  normal  activities,  it  has  been  necessary  to 
make  a  wide  detour  of  investigation  in  two  directions.  The  first  of  these 
has  consisted  in  a  study  of  the  microscopical  appearances  of  lymph  as 
compared  with  different  special  protoplasms  under  various  methods  of 
hardening  and  staining.  This  has  proved  to  be  a  matter  of  fundamental 
importance  to  histology  in  general,  and  has  demonstrated  that,  until  we 
are  able  to  gain  some  definite  notion  as  to  the  substances  in  question,  it  is 
useless  to  go  on  figuring  and  describing  "  granulations,"  and  "  fibrillse," 
"  alveoli,"  and  the  like. 

The  other  line  of  research  to  which  study  of  the  rhythms  of  the  nerve 
cell  has  led  logically  is  that  of  the  physiological  conditions  in  general 
which  underlie  and  determine  phases  of  animal  activity.  In  other  words, 
if  we  wish  to  learn  the  condition  of  nerve  cells  in  states  of  rest  and  fa- 
tigue, we  must  study  first  the  normal  rhythms  of  activity  and  rest  of  our 
animal.  Knowing  this,  we  may  be  able  to  examine  the  nerve  tissues  at 
any  desired  point  in  the  curve  of  functional  activity.  And  in  order  to 
gain  the  fundamental  laws  of  nervous  activity,  we  need  to  study  these 
rhythms  of  sleep  and  waking,  rest  and  activity,  which  make  up  the  normal 
flow  of  an  animal's  life,  in  a  series  of  animals.  This  fundamental  work 
has  not  been  done  for  more  than  one  or  two  forms  as  yet,  and  for  those 
only  in  a  preliminary  way.  Dr.  Aikin's  study  of  vorticella,  which 
showed  that  a  one-celled  animal  is  capable  of  continuous  activity  so  long 
as  food  and  environment  remain  suitable,  was  the  first  on  the  subject. 
Stewart's  experiments  on  the  influence  of  barometric  pressure  and  diet, 


112  Department  of 

including  alcohol,  on  the  diurnal  activity  of  rats  and  mice,  together  with 
Dr.  Hodge's  similar  work  on  dogs  and  squirrels,  serve  further  to  indicate 
the  possibilities  in  this  field.  These  studies  have  pointed  to  the  fact  that 
the  activity  of  each  animal  conforms  to  a  type  as  to  periods  and  rhythms 
which  is  characteristic  of  the  species,  and  that  the  total  amount  of  work 
developed  is  profoundly  influenced  by  physiological  conditions  thus  far 
investigated.  These  researches  have  been  suspended  for  the  present, 
but  it  is  hoped  to  push  the  work  in  the  near  future  along  two  main 
lines.  The  first  of  these  aims  to  discover  the  typical  rhythms  of  physio- 
logical activity  for  a  series  of  animals,  both  invertebrate  and  verte- 
brate. It  would  seem  that  these  physiological  types  are  of  even  greater 
ultimate  interest  and  philosophical  importance  than  the  purely  structural 
and  morphological  types  from  which  the  comparative  anatomists  have 
worked  out  the  evolutionary  series.  When  this  has  been  done,  we  shall 
be  in  position  for  the  first  time  in  the  history  of  biological  science  to 
study  human  rhythms  of  activity  and  repose  in  the  light  of  similar  rhythms 
of  the  animal  series,  and  to  gain,  possibly,  some  notion  as  to  a  norm  for 
human  work.  The  second  line  of  study  in  this  field  essays  to  analyze  the 
physiological  conditions  under  which  any  particular  animal  is  able  to 
develop  the  greatest  possible  amount  of  normal  activity.  This  is  no  less 
a  problem  at  bottom  than  the  study  of  the  physiological  conditions  which 
underlie  the  highest  possible  types  of  human  life  and  activity. 

The  question  naturally  arises  at  this  point  as  to  what  position  the 
biological  department  of  Clark  University  assumes  upon  some  of  the 
wider  aspects  of  the  science. 

Since  the  times  when  Aristotle  employed  the  armies  of  Alexander  the 
Great  to  collect  specimens  for  his  museums  from  all  the  then  known 
world,  the  greater  portion  of  biological  effort  has  been  directed  toward 
classification  and  naming  of  animal  and  plant  species.  The  uttermost 
corners  of  the  earth  have  been  searched  to  the  tops  of  the  mountains  and 
dredged  to  the  deepest  ocean  depths,  all  to  discover  some  new  species  of 
animal  or  plant,  while  the  common  plants  and  animals  of  our  dooryards 
are  known  scarcely  more  than  in  name.  This  classification  work,  ex- 
tending from  Aristotle  in  Greece  through  Linne  and  Cuvier,  Buffon 
and  Brehm,  to  Agassiz  in  America,  has  been  in  part  necessary  and  impor- 
tant. But,  when  it  is  possible  to  find  single  species  which  have  been 
christened  ten  or  even  twenty  times,  it  is  safe  to  insist  that  the  passion 
for  naming  things  has  been  carried  too  far.     This  passion  for  names  is 


Biology.  113 

characteristic  of  a  certain  period  in  infancy  in  the  individual,  and,  we 
may  hope,  in  the  growth  of  a  science  as  well ;  and  while  it  gives  the  best 
promise  for  the  future,  is  it  not  time  to  hope  that  this  phase  of  biology 
may  wane,  and  the  maturer  work  of  learning  the  really  important  facts 
concerning  animals  and  plants  be  seriously  undertaken  ?  These  facts  of 
paramount  importance  have  to  do  with  the  functions  of  species,  the  work 
species  do  in  the  world.  As  a  matter  of  fact,  to  work  in  classification  by 
methods  of  external  characters  the  monumental  work  of  Darwin  and 
Wallace  has  long  since  put  a  final  period.  Species  are  not  fixed  immu- 
tably, but  are  plastic  and  normally  variable.  Embryological  studies, 
even  by  Louis  Agassiz  himself,  proved  that  animals  repeat  simpler  stages 
of  organization  each  in  its  own  life  history.  With  the  doctrine  of  evolu- 
tion the  whole  method  of  the  science  has  been  changed.  Deeper  char- 
acters than  those  on  the  surface  must  be  discovered,  and  only  such  as 
reveal  blood  relationships  and  indicate  the  true  position  of  the  species  in 
the  line  of  evolutionary  descent  can  be  of  permanent  importance  in  the 
new  classification.  Thus  the  past  two  decades  have  been  devoted  in 
biological  laboratories  largely  to  tracing  most  minutely  the  embryology 
of  different  species,  and  in  exhaustive  studies  into  comparative  anatomy 
and  embryology  combined.  There  has  been  a  constant  gravitation,  natu- 
rally enough,  to  again  consider  the  findings  of  the  microscope,  arrange- 
ments of  cells,  and  all  the  infinite  variety  of  granule  and  rod  and  fibril  as 
fixed  entities,  rather  than  again  as  plastic  and  possibly  changing  with 
every  phase  of  functional  activity.  There  has  thus  been  no  limit  to  the 
careful  drawing  and  figuring  and  coloring  of  what  are  supposed  to  be 
important  structures  in  living  protoplasm.  This  may  all  be  well  enough 
as  pastime.  But  where  the  idea  of  functional  changes  has  been  left  out 
of  account,  the  work  is  builded  on  the  sand.  It  is  like  studying  and  map- 
ping the  positions,  forms,  and  colors  of  the  clouds  by  means  of  the  nice 
adjustments  of  the  telescope.  Many  of  the  books  of  the  past  decade  will 
be  museum  junk  before  1910,  if  they  are  not  already.  We  need  to  real- 
ize in  our  modern  laboratories  that  turning  the  crank  of  a  microtome  in 
and  of  itself  has  no  more  educational  value,  possibly  not  so  much,  as 
turning  the  crank  of  a  grindstone.  In  fact,  our  theories  of  laboratory 
research  and  even  of  laboratory  instruction  in  the  brief  period  in  which 
these  have  come  into  prominence  have  gone  far  astray.  In  drifting 
away  from  all  considerations  of  human  good  and  even  common  sense, 
our  modern  laboratory  work  is  in  the  same  danger  of  becoming  an  end  in 


114  Departinent  of 

itself  that  sunk  the  old  classification  into  a  worse  than  imbecile  waste  of 
time. 

Furthermore,  progress  is  the  word  which  has  characterized  every 
expression  of  the  purpose  of  the  biological  department.  The  advance- 
ment of  science  has  been  its  fundamental  raison  d'etre  from  the  beginning. 
There  is  little  danger  that  the  world  will  have  too  many  institutions  de- 
voted to  the  serious  work  of  advancing  science.  The  great  difficulty  has 
been,  and,  we  may  add,  still  is,  that,  after  a  period  of  great  achievement, 
the  inevitable  tendency  asserts  itself  to  spin  round  and  round  about  it  as 
though  there  were  nothing  else  ahead  worth  working  for.  The  endless 
discussions  of  the  past  two  decades  reminds  one  of  the  hollow  disputations 
of  the  scholastics.  The  coursing  over  and  over  again  of  the  ground 
covered  so  well  by  Darwin  and  Wallace,  and  even  by  Aristotle,  in  great 
part,  has  been  enough  to  raise  the  shades  of  some  of  these  good  men  to 
urge  us  to  cease  hairsplitting  and  trifling,  and  go  forward  into  the  great 
field  which  their  works  have  opened  up. 

Their  great  contributions  have  consisted  in  demonstrating  the  plas- 
ticity of  living  forms,  and  the  field  which  this  presents  is  that  of  infinite 
possibilities  of  perfection  and  utilization  in  the  future.  It  has  opened  up 
before  us,  instead  of  the  dead  finality,  the  idiotic  circle  with  its  endless 
round  of  "  vanity  of  vanities,"  of  the  old  philosophy,  an  infinite  future 
of  progress.  In  this  progress  Science  must  worthily  lead,  but  may  well 
hold  Art  by  the  hand,  lest  the  doing  of  science,  which  is  its  consummation 
in  virtue,  fall  behind,  and  Science,  herself,  languish  for  very  lack  of 
sustenance. 

"We  expect  great  help  for  the  present  status  of  biological  science  from 
Brooks's  "  Foundations  of  Zoology."  To  the  question  which  he  imagines 
Aristotle  to  ask :  "  Is  not  the  biological  laboratory  which  leaves  out  the 
ocean  and  the  mountains  and  meadows  a  monstrous  absurdity  ? "  this 
department  would  answer — Yes.  And  it  would  add  that  it  is  not  enough 
to  bring  our  laboratories  to  the  ocean  and  make  fine  trips  to  the  mountains 
and  the  ends  of  the  earth,  unless  these  great  factors  become  a  real  part  of 
the  scientific  quest. 

In  a  word,  with  the  so-called  discovery  and  naming  of  a  species  of 
animal  or  plant,  and  even  with  its  embryonic  and  adult  anatomization, 
biological  science  has  scarcely  touched  the  great  problem  which  the 
species  presents.  With  the  half  million  species  of  animals  and  plants  of 
which  Science  has  told  us  scarcely  more  than  the  names.  Art  has  stumbled 


Biology.  115 

haltingly  along,  with  all  too  little  help  from  Science,  toward  the  perfection 
and  utilization  of  a  very  few,  our  domesticated  species.  Even  with  these 
few  the  scientific  biology  of  no  single  one  has  been  adequately  worked  out, 
and  we  are  practically  in  the  beginnings  of  scientific  studies  as  to  the 
influence  of  environment  in  cultural  conditions,  and  as  to  the  possibilities 
for  improvement  in  cross  fertilization.  Biological  science  owes  to  the 
world  not  only  knowledge  of  the  name,  form,  and  structure  of  a  species ; 
it  owes  as  well  a  clear  statement  of  what  the  species  does,  considered  as  a 
force  in  nature ;  and  further,  the  method  by  which  this  force  can  best  be 
utilized.  And  this  is  no  whit  less  pure  science  because  incalculable 
human  values  attach  to  the  knowledge.  Biologically  we  are  now  at  a 
stage  comparable  from  the  standpoint  of  physical  science  with  that  of  the 
sail-boat  and  the  stage-coach,  before  science  had  discovered,  and  discov- 
ered a  way  to  utilize,  the  forces  of  steam  and  electricity.  And  we  find, 
when  we  study  carefully  what  one  animal  or  a  plant  can  c?o,  and  multiply 
this  by  the  number  of  individuals  in  the  species,  values  and  magnitudes, 
which  we  scarcely  possess  terms  to  express.  Add  to  the  total  amounts 
of  forces  which  different  species  represent,  the  nicety  of  adjustment, 
the  adaptation  of  means  to  ends,  the  intelligent  direction  of  the  forces, 
which  make  comparative  psychology  a  part  of  biology,  and  we  begin  to 
realize  the  importance  of  biology  as  a  science.  No  seed  is  too  small  to 
contain  the  power,  under  proper  conditions,  of  covering  the  world  with 
plants  of  its  kind  ;  and,  not  only  that,  but  generation  after  generation  it 
may  be  capable  of  indefinite  improvement.  The  most  minute  organisms, 
the  bacteria,  possess  very  few  interesting  features  of  form  or  structure 
that  we  are  able  to  discover,  but  they  have  the  power  to  determine  the 
ultimate  food  supply  of  all  animal  life,  on  the  one  hand ;  and,  on  the  other, 
to  cause  the  disease,  suffering,  and  death  of  untold  numbers  of  animals, 
and  even  human  beings.  Insects,  on  the  one  hand,  have  created  flowers 
and  fruits  by  their  work  of  cross  fertilization,  and,  on  the  other,  have  laid 
a  tax  on  human  industries  heavier  than  that  of  bad  government  and  even 
of  war. 

Since  the  side  of  function,  of  the  actual  work  which  a  species  can  do, 
presents  the  greatest  ultimate  value  connected  with  knowledge  of  living 
things,  if  modern  biology  does  not  go  forward  into  this  great  field,  its 
whole  past  history  from  Aristotle  down  will  be  an  arrested  development. 

The  laboratory  that  undertakes  this  work  must  be  a  unique  affair  as 
biological  laboratories  go  now.     It  should  have  greenhouses,  terraria  and 


116  Department  of 

aquaria,  aviaries  and  insectories,  in  order  to  provide  the  essential  elements 
of  normal  environment  where  the  life  and  work  of  species  may  be  conven- 
iently studied  in  both  their  daily  rhythms  and  in  their  larger  life  cycles. 
It  should  especially  have  easily  accessible  the  actual  normal  environment 
of  the  species  under  investigation,  the  pond,  ocean,  stream,  grove,  forest, 
hill,  mountain,  field,  and  garden,  where  results  obtained  in  the  laboratory 
can  be  readily  tested  and  confirmed  in  the  actual  environment  of  nature. 
In  fact,  during  favorable  seasons  much  of  this  line  of  laboratory  work 
might  well  be  done  out  of  doors.  A  laboratory  of  this  kind  need  not  be 
expensive,  but  should  consist  largely  of  rooms  adapted  for  individual 
investigators,  so  that  researches  upon  the  life  and  work  of  a  number  of 
different  forms  may  be  carried  on  with  the  least  possible  mutual  disturb- 
ance and  interference.  This  is  an  absolute  essential  to  investigations 
of  this  class.  It  should  also  be  provided  with  sunny  and  sanitarily 
perfect  quarters  for  not  only  keeping,  but  rearing  and  breeding,  a  con- 
siderable variety  of  animals. 

These  and  many  other  considerations  render  it  imperative,  if  work 
of  the  best  quality  is  to  be  turned  out,  that  a  biological  laboratory  have 
a  building  of  its  own.  At  present  this  lack  has  been  one  of  the  chief 
obstacles  to  prosecution  of  the  important  lines  of  work  indicated.  They 
cannot  be  successfully  studied  in  rooms  used  for  other  purposes,  or  in  a 
building  shaken  by  the  running  of  powerful  dynamos  and  other  heavy 
machinery.  Natural  rhythms  and  periods  of  rest  and  activity  may  be 
profoundly  influenced  by  these  disturbing  conditions,  and  results  thus 
largely  vitiated.  As  already  stated,  the  foundations  for  a  biological 
laboratory  have  been  laid,  and  an  inexpensive  building  would  greatly 
facilitate  the  work  of  the  department.  It  ought  to  be  erected  under 
the  idea,  now  gaining  ground,  that  a  laboratory  should  be  a  somewhat 
temporary  building,  which  could  be  altered  and  reconstructed  from  time 
to  time  as  new  problems  arise. 

The  matter  of  biological  nature  study  has  already  been  referred  to, 
and  it  is  the  opinion  that  such  a  research  laboratory  should  be  in 
organic  relationship  with  elementary  education  and  the  public  school. 
It  is  believed  that  this  side  of  nature,  the  side  of  movement  and  activity, 
is  the  natural  side  of  approach  for  the  child.  It  is  peculiarly  akin  to 
that  animism  of  childhood  which  projects  life  and  action  even  into 
inanimate  things.  It  is  this  side  of  living  nature,  which,  from  its 
intrinsic  fascinations   and  varied  affinities  with  the   passionate   activity 


Biology.  117 

of  child  life,  is  calculated  to  create  enduring  love  of  nature  ;  and  the 
vast  human  values  and  interests  connected  with  it  constitute  the  most 
natural  wellspring  for  love  of  science. 

In  line  with  this  idea,  two  nature-study  leaflets  have  already  been 
printed,  upon,  respectively,  the  "  Biology  of  the  Common  Toad  "  and  the 
"Biology  of  Our  Common  Birds."  Both  of  these  were  written  by  Dr. 
Hodge,  and  he  has  thus  far  assumed  all  financial  responsibility  for  their 
publication.  He  also  has  in  course  of  preparation  similar  studies  on  a 
series  of  biological  subjects,  insects,  fishes,  and  reptiles,  flowers,  fruit, 
and  forest  trees,  bacteria  and  moulds,  and  a  few  others,  which  will 
provide  ample  materials  for  nature  study  from  the  standpoint  above 
indicated  for  the  entire  school  course.  On  the  one  hand,  such  connection 
between  the  biological  laboratory  and  the  schools  will  furnish  channels 
for  the  distribution  of  information  to  the  public,  and,  on  the  other,  may 
be  made  to  supply,  not  only  stimulus,  but  assistance  to  its  work  as  well. 

Bacteriology  is  a  recently  created  department  of  biology  which  has 
claimed  recognition  as  an  independent  science  by  reason  of  its  wonder- 
ful development  since  about  1880,  when  the  discoveries  of  Koch,  Pasteur, 
and  Lister  revealed  the  causal  relations  which  exist  between  these 
minute  organisms  and  disease.  We  can  express  the  enormous  values 
of  scientific  knowledge  of  these  germs  only  in  terms  of  human  life  itself. 
And  it  is  a  worthy  refutation  of  the  charge  sometimes  brought  against 
science  that  it  disregards  the  welfare  of  humanity  that,  as  Professor 
Ludwig  said,  laboratories  devoted  to  other  lines  of  biological  work 
have  been  depopulated,  because  their  students  have  flocked  into  this 
new  and  important  field.  The  bacteria  are  coming  to  be  recognized  as 
one  of  the  most,  if  not  the  most,  important  element  in  the  environment 
of  animal  and  even  plant  species ;  hence  their  consideration  is  essential 
in  such  studies  as  have  been  outlined  above,  which  aim  to  determine 
the  influence  of  environmental  conditions  upon  the  activity,  health,  and 
vigor  of  species.  Still  the  pathological  side  will  not  be  able  long  to 
dominate  the  science  of  biology  ;  and  even  with  relation  to  diseased 
conditions,  the  side  of  normal  function,  physiology  proper,  must  remain 
preeminent.  In  fact,  it  may  even  now  be  stated  as  the  highest  contri- 
bution of  bacteriology,  that  it  has  revealed  the  fact  that  the  highest 
possible  health  level  is  the  best  practical  safeguard  against  inroads  of 
microbic  disease.  Still  the  great  importance  of  the  subject  has  made  it 
cause  for  regret  that  the  resources  of  the  department  have  not  permitted 


118  Deimrtment  of  Biology. 

the  establishment  of  a  well-equipped  bacteriological  laboratory.  The 
next  step  in  the  development  of  the  department  should  be  in  this 
direction. 

The  library  of  the  biological  department  has  been  selected  with  a 
view  to  making  it  the  best  possible  working  library  for  those  engaged  in 
biological  research. 


THE  DEPARTMENT  OF  PSYCHOLOGY. 

By  Edmund  Clark  Sanford. 

PAST  AND  PRESENT  STAFF,  i 

G.  Stanley  Hall,  Ph.D.,  LL.D.,  President  of  the  University  and  Professor 
of  Psychology  and  Education  since  1889. 

Henry  H.  Donaldson,  Ph.D.,  Assistant  Professor  of  Neurology,  1889-92. 

Clifton  F.  Hodge,  Ph.D.,  Assistant  in  Psychology,  1890-91 ;  Assistant  Pro- 
fessor of  Physiology  and  Neurology  since  1892. 

Edmund  C.  Sanford,  Ph.D.,  Instructor  in  Psychology,  1889-92;  Assistant 
Professor  of  Psychology  since  1892. 

William  H.  Buknham,  Ph.D.,  Docent  in  Pedagogy,  1890-92 ;  Instructor  in 
Pedagogy  since  1892. 

Benjamin  Ives  Gilman,  Instructor  in  Psychology,  1892-93. 

Alexander  F.  Chamberlain,  Ph.D.,  Lecturer  in  Anthropology  since  1892. 

Franz  Boas,  Ph.D.,  Docent  in  Anthropology,  1889-92. 

B.  C.  Burt,  A.M.,  Docent  in  Philosophy,  1889-90. 

Alfred  Cook,  Ph.D.,  Docent  in  Philosophy,  1889-90. 

Herman  T.  Lukens,  Ph.D.,  Docent  in  Pedagogy  since  1895. 

Arthur  MacDonald,  A.M.,  Docent  in  Ethics,  1889-91. 

Adolf  Meyer,  M.D.,  Docent  in  Psychiatry  since  1896. 

Charles  A.  Strong,  Docent  in  Philosophy,  1890-91. 

FELLOWS  AND  SCHOLARS. 

H.  Austin  Aikins,  Ph.D.,  Fellow  in  Psychology,  1892-93 ;  Honorary  Fellow, 

1893-94. 
Ernest  Albee,  Scholar  in  Psychology,  1889-90 ;  Fellow,  1890-91. 
Arthur  Allin,  Ph.D.,  Honorary  Fellow  in  Philosophy,  1895-96. 
N.  P.  Avery,  Scholar  in  Psychology,  1895-96. 
Thomas  P.  Bailey,  Jr.,  Ph.D.,  Fellow  in  Psychology,  1892-93. 

1  As  this  list  shows,  the  Department  of  Psychology  has  included,  Anthropology,  Crimin- 
ology, Neurology,  Psychiatry,  Education,  and  Philosophy.  The  report  of  work  in  Neurology 
has  been  incorporated  by  Dr.  Hodge  with  that  in  Physiology  and  Biology. 

119 


120  Department  of 

Henry  K.  Baker,  Student  in  Psychology,  1894-95 ;  Fellow,  1895-96 ;  Honor- 
ary Fellow,  1896-97,  and  1898-99. 

John  A.  Bergstrom,  Fellow  in  Psychology,  1891-94. 

Eugene  W.  Bohannon,  Scholar  in  Pedagogy,  1895-96 ;  Fellow  in  Psychology, 
1896-98. 

Frederick  E.  Bolton,  Honorary  Fellow  in  Psychology,  1897-98. 

Thaddeus  L.  Bolton,  Scholar  in  Psychology,  1890-91 ;  Fellow,  1891-93. 

Ernest  N.  Brown,  Scholar  in  Psychology,  1891-92. 

Elmer  B.  Bryan,  Scholar  in  Philosophy,  1898-99. 

William  L.  Bryan,  Fellow  in  Psychology,  1891-93. 

Frederic  Burk,  Scholar  in  Psychology,  1896-97 ;  Honorary  Fellow,  1897-98. 

Will  G.  Chambers,  Scholar  in  Psychology,  1897-98. 

Walter  Channing,  Honorary  Scholar  in  Psychology,  1889-90 ;  Honorary 
Fellow,  1890-92. 

Oscar  Chrisman,  Fellow  in  Pedagogy,  1892-94. 

Robert  Clark,  Scholar  in  Pedagogy,  Jan.,  1898-June,  1899. 

Charles  W.  Clinton,  Fellow  in  Psychology,  1897-98. 

Frederick  W.  Colegrove,  Honorary  Fellow  in  Psychology,  1896-99. 

Thomas  R.  Croswell,  Scholar  in  Pedagogy,  1895-97. 

Henry  S.  Curtis,  Fellow  in  Psychology,  1895-97. 

Arthur  H.  Daniels,  Fellow  in  Psychology,  1892-93. 

George  E.  Dawson,  Fellow  in  Psychology,  1895-97. 

Fletcher  B.  Dresslar,  Scholar  in  Psychology,  1891-93 ;  Fellow,  1893-94. 

Frank  Drew,  Scholar  in  Psychology,  1892-93;  Fellow,  1893-95. 

Frederick  Eby,  Scholar  in  Pedagogy,  1898-99. 

Stafford  C.  Edwards,  Scholar  in  Pedagogy,  1897-98. 

A.  Caswell  Ellis,  Scholar  in  Pedagogy,  1894-95 ;  Fellow  in  Psychology, 
1895-97. 

H.  L.  Everett,  Scholar  in  Psychology,  1896-97 ;  Honorary  Fellow,  1897-98. 

Daniel  Folkmar,  Fellow  in  Psychology,  1889-90. 

Clemens  J.  France,  Scholar  in  Psychology,  1898-99. 

J.  Irwin  France,  Scholar  in  Psychology,  1896-97. 

Alexander  Eraser,  Fellow  in  Psychology,  1891-92. 

John  P.  Fruit,  Scholar  in  Psychology,  1891-92. 

Henry  H.  Goddard,  Scholar  in  Psychology,  1896-97 ;  Fellow,  1897-99. 

Cephas  Guillet,  Scholar  in  Psychology,  1895-96 ;  Fellow,  1896-98. 

John  A.  Hancock,  Fellow  in  Pedagogy,  1893-94. 

S.  B.  Haslett,  Scholar  in  Psychology,  1898-99. 

Clark  W.  Hetherington,  Fellow  in  Psychology,  1898-99. 

tR.  C.  Hollenbaugh,  Ph.D.,  Scholar  in  Psychology,  1892-93.   Died  July  6, 1893. 

William  A.  Hoyt,  Scholar  in  Pedagogy,  1893-94. 

Edmund  B.  Huey,  Scholar  in  Psychology,  1897-98;  Fellow,  1898-99. 

D.  D.  Hugh,  Fellow  in  Psychology,  1895-96. 

John  P.  Hylan,  Fellow  in  Psychology,  1895-97. 


Psychology.  121 

TiLMON  Jenkins,  Scholar  in  Pedagogy,  1897-98. 

George  E.  Johnson,  Scholar  in  Pedagogy,  1893-94 ;  Fellow,  1894-95. 

E.  A.  KiRKPATKicK,  Scholar  in  Psychology,  1889-90 ;  Fellow,  1890-91. 

Milton  S.  Kistler,  Scholar  in  Pedagogy,  1897-98. 

Linus  W.  Kline,  Scholar  in  Psychology,  1896-97 ;  Fellow,  1897-98 ;  Honorary 

Fellow,  1898-99. 
William  O.  Krohn,  Ph.D.,  Fellow  in  Psychology,  March-June,  1892. 
E.  G.  Lancaster,  Scholar  in  Psychology,  1895-96  ;  Fellow,  1896-97. 
James  S.  Lemon,  Scholar  in  Psychology,  1891-93  ;  Student,  1893-94. 
James  E.  Le  Rossignol,  Ph.D.,  Fellow  in  Psychology,  May-July,  1892. 
James  H.  Leuba,  Scholar  in  Psychology,  1892-93 ;  Fellow,  1893-95 ;  Honorary 

Fellow,  1895-96. 
Ernest  H.  Lindley,  Fellow  in  Psychology,  1895-97. 
George  W.  A.  Luckey,  Fellow  in  Psychology,  1894-95. 
Frank  H.  McAssey,  Scholar  in  Psychology,  1898-99. 
George  F.  Metzler,  Ph.D.,  Fellow  in  Psychology,  1891-92, 
Dickinson  S.  Miller,  Fellow  in  Psychology,  1889-90. 
Herbert  Nichols,  Fellow  in  Psychology,  1889-91. 
C.  A.  Orr,  Scholar  in  Psychology,  1889-90. 
George  E.  Partridge,  Special  Student  in  Philosophy,  1895-96;   Scholar  in 

Psychology,  1896-98  ;  Fellow,  1898-99. 
T.  Richard  Peede,  Special  Student  in  Philosophy  and  Pedagogy,   1895-96 ; 

Honorary  Scholar  in  Philosophy,  1896-97. 
Daniel  E.  Phillips,  Scholar  in  Psychology,  1894-March,  95 ;  Honorary  Scholar, 

Jan.-June,  97 ;  Fellow,  1897-98. 
Jefferson  R.  Potter,  Scholar  in  Pedagogy,  1890-91. 
J.  0.  QuANTz,  Ph.D.,  Honorary  Fellow  in  Psychology,  1897-98. 
J.  F.  RiEGART,  Scholar  in  Psychology,  1890-91. 
Robert  J.  Richardson,  Fellow  in  Psychology,  1898-99. 
Erwin  W.  Runkle,  Ph.D.,  Honorary  Fellow  in  Psychology,  Jan.-June,  1899. 
Albert  Schinz,  Ph.D.,  Honorary  Fellow  in  Psychology,  1897-98. 
Alva  R.  Scott,  Honorary  Scholar  in  Psychology,  1894-95 ;  1896-97. 
Colin  A.  Scott,  Fellow  in  Psychology,  1894-96. 

E.  W.  Scripture,  Ph.D.,  Fellow  in  Psychology,  Jan.-June,  1891 ;  1891-92. 
Charles  H.  Sears,  Ph.D.,  Honorary  Fellow  in  Pedagogy,  1897-99. 
Albert  E.  Segsworth,  Honorary  Fellow  in  Psychology,  1893-94. 
John  C.  Shaw,  Scholar  in  Pedagogy,  1895-96 ;  Fellow  in  Psychology,  1896-97. 
Henry  D.  Sheldon,  Fellow  in  Pedagogy,  1897-99. 

Frederic  D.  Sherman,  Ph.D.,  Honorary  Fellow  in  Psychology,  1898-99. 
TosHiHiDE  Shinoda,  Honorary  Scholar  in  Pedagogy,  1889-90. 
Maurice  H.  Small,  Scholar  in  Psychology  and  Pedagogy,  1895-96 ;  Fellow  in 

Psychology,  1896-98. 
WiLLARD  S.  Small,  Scholar  in  Psychology,  1897-98 ;  Fellow,  1898-99. 
Frank  E.  Spaulding,  Ph.D.,  Honorary  Fellow  in  Psychology,  1894-95. 


122  Departme7it  of 

Edwin  D.  Starbuck,  Fellow  in  Psychology,  1895-97. 

J.  Richard  Street,  Scholar  in  Pedagogy,  1895-96;   Fellow  in  Psychology, 

1896-98. 
Charles  H.  Thurber,  Honorary  Fellow  in  Pedagogy,  Jan.-April,  1899. 
Frederick  Tracy,  Fellow  in  Psychology,  1892-93. 
NoRMAx  Triplett,  Fcllow  in  Psychology,  1898-99. 

Gerald  M.  West,  Ph.D.,  Fellow  in  Anthropology,  1890-91 ;  Assistant,  1891-92. 
Guy  M.  Whipple,  Scholar  in  Psychology,  1897-98. 
MiNosuKE  Yamaguchi,  Scholar  in  Psychology,  1897-98. 
Albert  H.  Yoder,  Scholar  in  Pedagogy,  1893-94. 
Lewis  E.  York,  Scholar  in  Pedagogy,  1897-98. 


HISTORICAL  SKETCH  OF  THE  WORK  IN  GENERAL  PSYCHOLOGY. 

The  ten  years  covered  by  the  history  of  the  Psychological  Depart- 
ment in  this  University  have  been  eventful  in  the  history  of  Psycho- 
logical Science  in  the  country  at  large. 

Before  1880  the  science  was  taught  as  a  stepping-stone  to  metaphysics 
and  ethics ;  its  method  was  chiefly  introspective ;  laboratories  were 
unheard  of;  and  genetic  and  comparative  psychology  were  a  terra 
incognita.  During  the  early  part  of  the  eighties,  however,  the  idea 
that  psychology  was  an  independent  science,  to  be  advanced  by  experi- 
ment and  systematic  observation,  was  gradually  taking  root,  and  in 
1888  and  1889  began  a  vigorous  growth.  New  interest  was  taken 
in  the  subject,  laboratories  began  to  be  opened,  and  a  special  journal 
was  started  for  the  publication  of  psychological  investigations  (^The 
American  Journal  of  Psychology').  Since  that  time  the  interest  has 
continued ;  the  laboratories  have  increased  at  the  rate  of  three  or 
four  a  year  till  they  now  number  between  thirty  and  forty,  are  found 
in  almost  all  the  leading  universities  of  the  country,  are  often  liberally 
supported,  and  in  some  cases  surpass  the  best  European  laboratories 
in  equipment ;  and  many  workers  trained  at  home  and  abroad  have 
entered  the  field.  In  1892  the  American  Psychological  Association 
was  started,  and  now  numbers  over  one  hundred  members,  nearly  all 
actively  interested  in  psychological  teaching  or  investigation.  A  little 
later  genetic  and  comparative  psychology  appeared  in  an  awakened  interest 
in  the  study  of  childhood;   and  more  recently  still  have  been  extended 


PsycJiology.  123 

into  a  new  and  fruitful  study  of  the  mind  and  habits  of  animals. 
Since  189-4  a  second  psychological  journal,  The  Psychological  Review^ 
has  been  published;  and  many  articles  of  psychological  interest  appear 
in  the  Pedagogical  Seminary  (especially  on  Child  Study)  and  in  the 
other  educational  magazines.  It  is  with  such  a  period  of  vigorous 
interest  in  psychology  and  of  rapid  growth  in  facilities  that  our  own 
ten  years'  history  coincides. 

In  turning  now  to  this  more  particularly,  I  shall  speak  first  of 
the  work  in  experimental  psychology,  which,  though  by  no  means 
the  whole  of  the  new  movement,  has  been  so  far  rather  its  centre  and 
characteristic  mark,  and  afterward  of  that  of  a  more  general  character. 

The  distinctive  feature  of  American  laboratories  generally  is  the 
extent  to  which  they  are  used  for  psychological  teaching  as  distinct 
from  psychological  investigation.  Both  foreign  and  home  laboratories 
have  the  double  purpose  of  instruction  and  research,  but  in  the  American 
laboratories  a  little  greater  emphasis  seems  to  be  laid  on  their  pedagogical 
usefulness.  This  emphasis  is  doubtless  due  in  part  to  more  deep- 
seated  differences  between  American  and  foreign  universities,  but  it 
has  been  favored  also  by  the  feeling  that  a  general  acquaintance  with 
laboratory  problems  and  methods  should  precede  the  undertaking  of 
original  investigation.  In  the  case  of  the  Clark  laboratory,  it  has 
been  further  enforced  by  the  number  of  students  of  pedagogy  for  whom 
a  psychological  groundwork  must  be  provided. 

The  advantage  of  laboratory  teaching  of  psychology  is  that  of  all 
proper  laboratory  teaching,  namely,  that  the  student  is  brought  face 
to  face  with  that  about  which  he  is  studying,  and  knows  the  thing 
itself  at  first  hand  rather  than  what  some  text-book  or  lecturer  may 
say  about  it.  For  those  who  intend  to  take  up  experimental  investi- 
gation later,  it  is  of  course  the  natural  apprenticeship. 

Such  elementary  laboratory  teaching  demands  some  sort  of  manual 
or  guide  that  can  be  put  into  the  hands  of  the  students,  a  fact  that 
became  painfully  evident  in  the  first  years  of  the  department ;  and  as 
at  the  time  none  whatever  existed,  it  was  necessary  to  make  one.  A 
beginning  was  made  with  manuscript  sheets  struck  off  on  the  mimeo- 
graph. Later  these  were  worked  over  in  part  in  a  series  of  articles  in  the 
Journal  of  Psychology^  and,  finally,  again  revised  and  enlarged,  this  part 
was  regularly  published,  six  chapters  in  1894,  and  the  remainder  last  year, 
making  altogether  a  volume  of  about  450  pages  covering  the  topics  of 


124  Department  of 

sensation  and  perception.  This  work  seems  to  have  supplied  a  genuine 
need  —  at  least,  has  met  with  a  wide  acceptance  in  American  laboratories. 
Up  to  the  year  just  passed  the  laboratory  course  has  not  extended 
beyond  the  usual  laboratory  topics  of  sensation  and  perception,  reaction- 
times,  Weber's  law,  and  the  like.  But,  beginning  with  the  year  1898-99, 
an  important  enlargement  was  made  by  the  addition  of  laboratory 
practice  in  comparative  psychology.  Under  the  special  guidance  of 
Dr.  Kline,  opportunities  have  been  given  for  the  study  of  the  habits 
and  mental  life  of  a  number  of  more  or  less  typical  animals.  Starting 
with  the  microscopical  amceba,  paramecium,  and  vorticella,  the  list  has 
been  extended  upward  to  include  earthworms,  slugs,  fish,  chickens, 
white  rats,  and  kittens.  Though  lectures  have  been  regularly  delivered, 
demonstrations  made,  and  seminaries  held  in  connection  with  the  labora- 
tory work,  the  development  of  this  practice  course  in  both  experimental 
and  comparative  psychology,  together  with  the  manual  mentioned  and 
the  similar  though  briefer  work  of  Dr.  Kline,  is  regarded  as  the  most 
important  product  of  the  Clark  laboratory  on  its  teaching  side. 

The  scientific  work  of  the  laboratory  has  resulted  in  ten  or  twelve 
extended  researches  and  in  a  considerable  number  of  briefer  studies.  It 
is  not  easy  in  short  space  to  give  an  intelligible  account  of  studies  upon  a 
variety  of  topics  so  considerable  as  these  have  covered,  but  it  has  seemed 
to  the  writer  that  a  list  of  the  titles  of  papers  published,  with  a  few 
lines  of  explanation  where  necessary,  might  serve  the  purpose. 

STUDIES  FROM  THE  PSYCHOLOGICAL  LABORATORY. 
Time  and  Rhythm. 

Nichols  :  The  Psychology  of  Time.  Am.  Jour,  of  Psy..,  Vol.  3,  pp. 
453-529,  and  Vol.  4,  pp.  60-112  (1891).  (Dissertation.)  Repub- 
lished in  book  form  by  Henry  Holt,  New  York,  1891. 

A  general  discussion  of  the  time  problem.  The  experimental  portion 
shows  that  a  period  of  practice  in  keeping  time  at  a  slow  rate  tends  to 
slow  a  quicker  rate  tried  immediately  afterward,  and  vice  versa,  thus 
demonstrating  a  dependence  of  time  j  udgments  upon  artificially  acquired 
rhythms. 

Bolton,  T.  L.  :  On  the  Discrimination  of  Groups  of  Rapid  Clicks. 
lUd.,  Vol.  5,  pp.  294-310  (1893). 

An  indirect  determination  of  the  fineness  of  discrimination  for  very 
short  periods  of  filled  time. 


Psychology.  125 

Bolton,  T.  L.  :  Rhythm.  Ibid.,  Vol.  6,  pp.  145-238  (1894).  (Dis- 
sertation.) 

A  general  account  of  the  subject.  The  experimental  portion  deals 
with  the  subjective  rhythms  observed  in  uniform  series  of  sounds,  and 
with  the  structure  of  the  rhythmic  feet  which  result  when  sounds  of 
different  length  or  intensity  are  regularly  introduced  in  an  otherwise 
uniform  series. 

Hamlin,  Alice  J.  :  On  the  Least  Observable  Interval  between  Stimuli 
addressed  to  Disparate  Senses  and  to  Different  Organs  of  the  Same 
Sense.     Ibid.,  Vol.  6,  pp.  564-575  (1895). 

Experimental  determination  of  the  interval  that  must  separate  nearly 
simultaneous  sensations  in  order  that  their  order  may  be  recognized. 
Experiments  with  clicks  and  flashes,  flashes  and  shocks,  separate  clicks 
heard  by  the  two  ears,  etc.,  and  with  indifferent  and  with  specially 
directed  attention. 

Whipple:  On  Nearly  Simultaneous  Clicks  and  Flashes.  Ibid. ,Yo\. 
10,  pp.  280-286  (1899). 

A  study  of  the  reason  for  the  difference  between  the  results  of 
Dr.  Hamlin  and  of  earlier  European  observers  in  the  matter  of  which 
order  of  stimuli  (click-flash  or  flash-click)  could  be  more  readily  recog- 
nized. Dr.  Hamlin's  results  are  confirmed  and  the  difference  proved  not 
to  lie  in  the  fact  that  the  European  observers  had  made  use  of  series  of 
pairs  of  clicks,  which  had  been  supposed  a  possible  cause. 

Memory. 

Bolton,  T.  L.  :  The  Growth  of  Memory  in  School  Children.  Ibid., 
Vol.  4,  pp.  362-380  (1892). 

A  study  by  the  memory-span  method  on  upwards  of  fifteen  hundred 
children,  made  in  connection  with  the  anthropometric  studies  of  Dr. 
Boas,  together  with  a  theoretical  treatment  of  the  statistical  curves 
obtained. 

Bergstrom  :  Experiments  upon  Physiological  Memory  by  Means  of 
the  Interference  of  Associations.  Ibid.,  Vol.  5,  pp.  356-369 
(1893). 

The  Relation  of  the  Interference  to  the  Practice  Effect  of  an 
Association.     Ibid.,  Vol.  6,  pp.  433-442  (1894). 

An  Experimental  Study  of  Some  of  the  Conditions  of  Mental 


126  Dejxirtment  of 

Activity.    lUd.,  Vol.  6,  pp.  247-274  (1894).    (These  three  papers 
were  united  to  form  a  Dissertation.) 

A  pack  of  eighty  cards  (eight  cards  each  of  ten  different  kinds)  is  sorted 
according  to  the  kinds,  and  after  an  interval  re-sorted,  but  with  such  an 
arrangement  that  each  kind  occupies  a  different  place  on  the  table.  The 
second  sorting  takes  longer  because  of  interference  between  the  new  as- 
sociations and  those  formed  in  the  first  sorting,  and  the  excess  of  time 
required  measures  indirectly  the  persistence  of  the  first  set  of  associa- 
tions. The  first  paper  gives  curves  showing  the  rate  of  falling  away  of 
the  first  associations  (curves  of  forgetting)  determined  by  this  method. 
The  second  paper,  by  an  ingenious  application  of  the  same  method, 
shows  that  the  interference  power  of  any  association  is  practically  equal 
to  the  fixity  given  it  by  practice,  —  in  other  words,  "  that  the  work  of 
breaking  up  a  habit  is  roughly  proportional  to  the  work  of  forming  it." 
The  third  paper  gives  determinations  of  the  variations  in  mental  abil- 
ity during  the  work  hours  of  the  day  made  upon  several  different  sub- 
jects and  with  different  sorts  of  tests. 

Daniels  :    The  Memory  After-image  and  Attention.     Ibid.,  Vol.  6, 
pp.  558-564  (1895). 

The  aim  was  to  measure  the  native  persistence  of  bare  impressions 
as  distinguished  from  that  which  they  show  when  received  with  atten- 
tion and  held  by  association.  The  time  was  found  to  be  very  short,  not 
more  than  five  or  ten  seconds. 

Smith,  Theodate  L.  :    On   Muscular  Memory.     Ibid.,  Vol.  7,  pp. 
453-490  (1896). 

A  painstaking  comparative  study  of  the  memory  of  nonsense  syl- 
lables learned  with  and  (as  far  as  possible)  without  the  cooperation  of 
the  vocal  mechanism.  The  memory  assisted  by  even  incipient  move- 
ments was,  in  all  cases,  distinctly  better,  —  a  result  further  confirmed 
by  a  similar  study  on  various  combinations  of  the  manual  signs  of  the 
deaf-mute  alphabet  learned  with  and  without  execution  of  the  hand 
postures  involved. 

COLEGEOVE:    The  Time  required  for  Recognition.     Ibid.,  Vol.  10, 
pp.  286-292  (1899). 

A  chronoscopic  study  of  the  time  required  for  deciding  whether  a 
picture  suddenly  presented  had  been  seen  before  or  not. 


Psychology.  127 


Psychology  of  Movement. 


Bryan,  W.  L.  :  On  the  Development  of  Voluntary  Motor  Ability. 
Ibid.,  Vol.  5,  pp.  125-204  (1892).     (Dissertation.) 

A  study  of  the  rate,  precision,  and  strength  of  voluntary  movements 
in  the  case  of  adults,  and  of  a  large  number  of  school  children  from  six 
to  sixteen  years  old.  Differences  due  to  fatigue,  to  increasing  age,  to 
sex,  to  bilateral  asymmetry,  and  the  like,  are  carefully  worked  out;  the 
mathematical  treatment  of  the  statistics  (thanks  in  part  to  suggestions 
from  Dr.  Boas)  is  unusually  full  and  rigid. 

Reigart  and  Sanfokd:  On  Reaction-times  when  the  Stimulus  is 
Applied  to  the  Reacting  Hand.  Ibid.,  Vol.  5,  pp.  351-355 
(1893). 

The  experiments  bring  into  question  the  statement  of  Exner  that 
reactions  are  slower  when  the  stimulus  is  applied  to  the  reacting  hand. 

Hancock:  A  Preliminary  Study  of  Motor  Ability.  Pedagogical 
Seminary,  Vol.  3,  pp.  9-29  (1891). 

The  Relation  of  Strength  to  Flexibility  in  the  Hands  of  Men 
and  Children.     Ibid.,  Vol.  3,  pp.  308-313  (1895). 

The  first  is  a  study  of  the  spontaneous  movements  of  school  children 
from  five  to  seven  years  old,  —  of  the  swayings  and  tremors  displayed 
in  efforts  to  stand  still  with  eyes  open  or  closed,  or  to  hold  the  hand  or 
forefinger  still,  —  movements  analogous  to  those  of  nervous  disease.  The 
second  paper  shows  for  the  persons  tested  (20  men,  22  boys,  and  11 
girls),  greater  flexibility  in  the  hands  of  the  men  as  measured  by  the 
extent  to  which  the  joints  could  be  flexed  voluntarily.  Both  papers  are 
of  avowedly  pedagogical  interest. 

Lancaster  :  Warming  Up.  Colorado  College  Studies,  Vol.  7,  pp. 
16-29  (1898). 

Based  upon  ergographic  experiments. 

Sensation  and  Perception. 

Scripture  :  Einige  Beobachtungen  iiber  Schwebungen  und  Differenz- 
tone.     Philos.  Studien,  Vol.  7,  pp.  630-632  (1892). 

A  brief  experimental  study  of  beats  and  difference  tones  produced  by 
forks  sounding  separately  on  either  side  of  the  head. 


128  Department  of 

Dresslar:  On  the  Pressure  Sense  of  the  Drum  of  the  Ear  and  "Fa- 
cial Vision."    Am.  Jour,  of  Psy.,  Vol.  5,  pp.  344-350  (1893). 

The  study  shows  that  the  faculty  of  the  blind  of  recognizing  the 
presence  or  absence  of  neighboring  objects,  which  has  been  credited  to 
some  sort  of  obscure  visual  sensation  in  the  skin  of  the  face,  or  to  sen- 
sations of  pressure  mediated  by  the  drum  of  the  ear,  is  probably  a 
matter  of  hearing. 

Krohn  :  An  Experimental  Study  of  Simultaneous  Stimulation  of  the 
Sense  of  Touch.  Journal  of  Nervous  and  Mental  Disease,  N.  S., 
Vol.  18,  pp.  169-184  (1893). 

Based  chiefly  on  experiments  made  in  the  Clark  laboratory. 

Leuba:  a  New  Instrument  for  Weber's  Law,  with  Indications  of  a 
Law  of  Sense  Memory.  Am.  Jour,  of  Fsy.,  Vol.  5,  pp.  370-384 
(1893). 

Weber's  law  demonstrated  in  the  classification  of  artificial  stars. 
The  law  of  sense  memory  suggested  is  that  memories  of  intensities  of 
sensation  tend  to  shift  toward  the  middle  of  the  usual  scale  of  intensities. 

Dresslar  :  A  New  Illusion  for  Touch  and  an  Explanation  for  the 
Illusion  of  Certain  Cross  Lines  in  Vision.  Ibid.,  Vol.  6,  pp. 
275-276  (1894). 

This  illusion  is  similar  to  that  of  the  PoggendorfE  illusion  in  vision, 
and  the  obvious  explanation  in  the  case  of  the  touch  illusion  is  extended 
to  the  visual  one. 

Sanford:  a  New  Visual  Illusion.     Science,  Feb.  17,  1893. 
A  visual  illusion  involving  false  judgments. 

Dresslar  :  Studies  in  the  Psychology  of  Touch.  Am.  Jour,  of  Psy., 
Vol.  6,  pp.  313-368  (1894).     (Dissertation.) 

The  study  is  in  three  sections :  1.  On  the  Education  of  the  Skin  with 
the  ^sthesiometer,  particularly  of  its  bilateral  effects ;  2.  Experiments 
on  Filled  and  Open  Space  for  Touch,  showing  that  filled  space  seems 
larger  when  the  finger  moves  over  it,  or  when  the  extents  compared  are 
moved  under  the  resting  finger ;  3.  On  Apparent  Weight  as  affected  by 
Apparent  Size  and  Shape  —  tests  upon  school  children  and  adults. 


Psychology.  129 

Circulation  and  Respiration. 

Dawson  :  Effects  of  Mental  States  upon  Circulation. 

(Records  in  the  instructor's  hands  but  not  worked  up  as  yet.) 
Preliminary  note  in  the  Proc.  of  the  Am.  Psychological  Ass'n, 
Psychological  Review,  Vol.  4,  pp.  119-121  (189T). 

An  extended  study  made  with  the  plethysmograph  applied  simidtane- 
ously  to  the  hand  and  eye. 

Whipple  :  The  Influence  of   Forced   Respiration  on  Psychical  and 
Physical  Activity.     Am.  Jour,  of  Pay.,  Vol.  9,  pp.  560-571  (1898). 

The  effect  of  very  rapid  breathing  on  eight  simple  tasks  involving 
sensory  or  motor  activities,  or  both.  Effects  slight  in  most  cases ; 
physical  strength  and  endurance  seem  to  be  increased,  while  discrimi- 
native powers  seem  to  be  depressed. 

Comparative  Psychology. 

Kline  :  Methods  in  Animal  Psychology.     Ihid.^  Vol.  10,  pp.  256-279 
(1899). 

Discussion  of  methods,  and  presentation  of  the  results  of  experiments 
upon  vorticellae,  wasps,  chicks,  and  white  rats. 

Small,  W.  S.  :    Notes  on  the  Psychic  Development  of  the  Young 
White  Rat.     Ihid.,  Vol.  11,  pp.  80-100  (1899). 

The  study  consists  of  a  careful  record  of  the  bodily  and  mental 
development  of  the  white  rat  from  birth  onward  for  a  number  of  weeks. 

Studies  on  Miscellaneous  Topics. 

Calkins,  Mary  Whiton  :  Statistics  of  Dreams.     Ihid.,  Vol.  5,  pp. 
311-343  (1893). 

A  careful  analytical  and  statistical  study  of  dreams,  recorded  immedi- 
ately after  waking  by  two  subjects  during  a  period  of  six  or  eight 
weeks.  An  effort  to  get  as  full  a  picture  as  possible  of  normal  dream- 
life. 

LucKEY :    Some  Recent  Studies  of  Pain.     Ihid.,  Vol.  7,  pp.  108-123 
(1895). 

A  review  of  recent  literature  on  the  physiology  and  psychology  of 
pain. 


130  Department  of 

Miles,  Caroline  :   A  Study  of  Individual  Psychology.     Ibid.,  Vol. 
6,  pp.  534-558  (1895). 

A  questionnaire  study  of  a  number  of  special  points,  made  on  one 
hundred  students  in  Wellesley  College.  Such  topics  are  considered  as : 
How  do  you  know  your  right  hand  from  your  left  ?  How  do  you  con- 
centrate attention  ?  Fears  as  children  ?  Things  causing  anger  ?  Favor- 
ite color?  Earliest  memories?  Early  ideals?  etc.  (This  study  and 
the  preceding,  though  not  experimental,  were  made  in  connection  with 
the  work  of  the  laboratory.) 

Drew:    Attention:    Experimental  and  Critical.      Ibid.,  Vol.  7,  pp. 
533-576   (1896).     (Dissertation.) 

The  experimental  portion  of  this  paper  consists  of  three  sections : 

1.  Eeaction  and  Association  Times  with  Differing  Degrees  of  Distraction ; 

2.  A  Qualitative  Study  of  Associations  with  Full  and  with  Distracted 
Attention;  3.  A  Study  of  the  Apparent  Order  of  nearly  Simultaneous 
Stimuli  with  variously  Directed  Attention. 

Hylan  :  The  Fluctuation  of  Attention.     Psychological  Review,  Mono- 
graph Supplement,  No.  6,  pp.  1-78  (1898). 

An  experimental  and  expository  paper,  the  experiments  approaching 
the  question  in  several  different  ways. 

HuEY :  Preliminary  Experiments  in  the  Physiology  and  Psychology 
of  Reading.     Am.  Jour,  of  Psy.,  Vol.  9,  pp.  575-586  (1898). 

Tests  of  rate  of  reading  in  vertical  and  horizontal  directions,  of  the 
importance  for  recognition  of  the  first  and  last  parts  of  words,  and  of 
the  actual  movements  of  the  eye  in  reading,  determined  by  apparatus 
attached  to  the  eye.  This  study  was  continued  during  the  year  1898-99, 
with  results  that  are  nearly  ready  for  publication. 

Technical  Matters. 

The   following  papers  have   been   chiefly  concerned  with  technical 
matters  and  apparatus. 

Scripture  :  Psychological  Notes.     Ibid.,  Vol.  4,  pp.  577-584  (1892). 

On  the  method  of  regular  variation ;  The  least  perceptible  variation 
in  pitch ;  The  faintest  perceptible  sound  ;  Notation  for  intensity;  A  con- 
stant blast  for  acoustical  purposes ;  Some  psychological  terms. 

Scripture  :  An  Instrument  for  Mapping  Hot  and  Cold  Spots  on  the 
Skin.     Science,  Vol.  19,  p.  258  (1892). 


Psijcliology.  131 

Dkesslar:  a  New  and  Simple  Method  for  comparing  the  Perception 
of  Rate  of  Movement  in  the  Direct  and  Indirect  Fields  of  Vision. 
Am.  Jour,  of  Psy.,  Vol.  6,  p.  312  (1894). 

Sanfoed:  a  Simple  and  Inexpensive  Chronoscope.  Ibid.,  Vol.  3,  pp. 
174-181  (1890). 

A  New  Pendulum  Chronograph.  Ibid.,  Vol.  5,  pp.  384-389 
(1898). 

Some  Practical  Suggestions  on  the  Equipment  of  a  Psychologi- 
cal Laboratory.    Ibid.,  Vol.  5,  pp.  429-438  (1893). 

Notes  on  New  Apparatus.     Ibid.,  Vol.  6,  pp.  575-584  (1895). 

The  Vernier  Chronoscope.     Ibid.,  Vol.  9,  pp.  191-197  (1898). 


While  these  studies  have  been  going  on  in  the  laboratory,  the  work 
in  philosophy  and  education,  and  in  the  non-laboratory  sections  of 
psychology,  has  been  carried  forward  with  perhaps  even  greater  vigor. 
President  Hall,  Dr.  Burnham,  Dr.  Boas,  Dr.  Chamberlain,  Dr.  Meyer, 
Messrs.  MacDonald,  Strong,  Gilmau,  and  others,  have  lectured  on  various 
aspects  of  the  history  of  philosophy,  pedagogy,  psychiatry,  aesthetics, 
criminology,  and  anthropology.  Some  account  of  the  work  in  education, 
anthropology,  and  psychiatry  will  be  found  below  in  the  special  reports 
of  Drs.  Burnham,  Chamberlain,  and  Meyer;  the  rest  will  be  spoken  of 
here. 

The  work  of  instruction  has  been  carried  on  by  means  of  seminaries  as 
well  as  lectures,  and  to  a  great  extent  also  in  the  more  informal  but  most 
effective  way  of  personal  conference  with  individual  students. 

It  is  not  possible  from  data  now  at  hand  to  give  a  complete  list  of  the 
courses  given  by  President  Hall,  but  at  different  times  he  has  lectured 
upon  the  History  of  Philosophy,  Ancient,  Mediaeval,  and  Modern  (taking 
philosophy  in  a  sense  wide  enough  to  include  psychology,  education,  and 
medicine) ;  on  Cosmology,  on  General  Psychology,  on  Morbid  Psychology 
(with  clinics  at  the  Worcester  Lunatic  Hospital),  on  Genetic  Psychology 
(both  in  the  animal  series  and  in  the  child),  Educational  Philosophy  and 
Practice,  Child  Study,  Adolescence,  Curricula,  Teaching  of  Special  Sub- 
jects, and  upon  other  pedagogical  topics.     In  addition  to  these  lectures, 


132  Department  of 

President  Hall  has,  almost  from  the  first,  conducted  a  weekly  seminary, 
meeting  in  the  evening  at  his  own  house.  Here  members  of  the  depart- 
ment have  reported  on  the  progress  of  their  investigations  and  received 
the  benefit  of  mutual  criticism,  or  have  united  in  the  study  of  some 
special  author  or  topic.  Notes  of  the  discussions  of  the  seminary  during 
a  period  when  chief  attention  was  given  to  Plato  have  been  published  by 
Dr.  H.  Austin  Aikins  in  the  Atlantic  Monthly  (September  and  October, 
1894),  under  the  title,  "From  the  Reports  of  the  Plato  Club."  Presi- 
dent Hall  has  also  directed  the  research  of  the  greater  part  of  the  men 
in  the  department,  recommending  topics,  methods,  literature,  and  lines  of 
thought,  and  in  some  cases  has  gone  so  far  as  to  enter  into  joint  author- 
ship with  the  students,  taking  their  incomplete  results  and  putting  them 
into  shape  for  publication. 

In  the  first  years  after  the  opening  of  the  University,  President  Hall 
was  assisted  in  the  philosophical  teaching  by  Dr.  Alfred  Cook,  Dr.  B.  C. 
Burt,  and  Mr.  C.  A.  Strong  as  Docents.  During  the  year  1889-90,  Drs. 
Burt  and  Cook  gave  courses  on  Greek  philosophy  and  on  modern  philos- 
ophy from  Locke  to  Kant;  and  in  1890-91,  Mr.  Strong  gave  a  brief  course 
on  the  history  of  psychology  among  the  Greeks  from  Thales  to  Aristotle, 
—  an  abstract  of  the  lectures  being  later  published  in  the  American  Jour- 
nal of  Psychology,  Vol.  4,  pp.  177-197  (1891).  During  1892-93,  Mr.  Ben- 
jamin Ives  Gilman,  as  Instructor  in  Psychology,  lectured  on  Pleasure  and 
Pain,  and  pursued  independent  investigations  on  the  theory  of  musical 
consonance.  Abstracts  of  his  lectures  are  to  be  found  in  the  American 
Journal  of  Psychology,  Vol.  6,  pp.  1-60  (1893).  Mr.  Arthur  MacDonald, 
as  Docent  in  Ethics,  devoted  himself  to  theoretical  and  practical  studies 
in  criminology,  lecturing  on  that  topic  during  the  first  year  of  the 
University  and  conducting  a  seminary,  with  occasional  lectures,  during 
the  second.  Since  1891  all  the  philosophical  teaching  of  the  department 
has  been  done  by  President  Hall  himself. 

The  research  of  this  section  of  the  psychological  department  has  been 
devoted  for  the  most  part  to  questions  that  are  too  large  and  too  unman- 
ageable for  successful  treatment  in  the  laboratory,  —  questions  of  the 
origin  and  development  of  mental  life  in  the  race  and  in  the  child,  of 
adolescence  and  sex,  of  emotion,  of  religion,  and  the  like.  Its  scope  and 
nature  will  be  apparent  from  the  following  list  of  studies:  — 


Psychology.  133 

Child  Study  and  Psychogenesis. 

Tracy:  The  Language  of  Childhood.     Am.  Jour,  of  Psy.^  Vol.  6,  pp. 
107-138  (1893). 

The  Psychology  of  Childhood.  Boston,  1893.  94  pp.  (Includes 
a  reprint  of  the  preceding.)     (Dissertation.) 

The  first  paper  is  a  careful  study  of  extant  data  on  the  physiology, 
phonetics,  and  psychology  of  infant  language,  together  with  new  mate- 
rial gathered  by  the  author.  The  second  is  a  similar  treatment  of 
sensation,  emotion,  intellection,  and  volition  as  they  appear  in  very 
young  children. 

Shaw  :  A  Test  of  Memory  in  School  Children.     Pedagogical  Semi- 
nary, Vol.  4,  pp.  61-78  (1896). 

An  account  of  tests  made  with  a  carefully  prepared  story,  which  was 
read  to  the  children  to  test  memory  and  lines  of  greatest  interest. 
Statistics  of  about  seven  hundred  papers  from  children  ranging  from  the 
third  year  of  school  life  to  those  in  the  higher  classes  of  the  high  school. 

Hall  and  Ellis:    A  Study  of   Dolls.     Ihid.,  Vol.  4,  pp.  129-175 
(1896). 

A  study  of  the  various  aspects  of  the  interest  in  dolls  and  of  ways  in 
which  they  are  used  in  play,  based  upon  numerous  replies  to  two  qii.es- 
tionnaires. 

Small,  M.  H.  :    The  Suggestibility  of  Children.     Ihid.,  Vol.  4,  pp. 
176-220  (1896). 

A  record  of  experiments  both  on  groups  of  children  and  on  separate 
individuals,  together  with  a  large  number  of  returns  from  a  question- 
naire, with  pedagogical  inferences  and  applications. 

Curtis  :  Inhibition.   lUd.,  Vol.  6,  pp.  65-113  (1898).    (Dissertation.) 

The  four  sections  of  the  paper  present :  1.  A  Summary  of  Facts  and 
Theories,  Psychological,  Biological,  and  Neurological ;  2.  An  Account  of 
the  Influence  of  Different  forms  of  Activity  on  one  Another ;  3.  A  Study 
of  Kestlessness  in  Children ;  and  4.  Pedagogical  Inferences  from  the  Fore- 
going. The  third  section  gives  results  of  experiments  and  observations 
by  the  author  together  with  questionnaire  returns.  The  term  "  inhibition  " 
is  taken  in  a  very  wide  sense. 

Partridge:  Reverie.     Ihid.,  Vol.  5,  pp.  445-474  (1898). 

A  study  of  337  questionnaire  returns  on  day  dreams  and  related  phe- 
nomena.    The  physical  signs,  the  subjective  state,  the  causes  and  condi- 


134  Department  of 

tions,  the  content,  and  the  awakening  are  considered.  An  appendix 
contains  records  of  the  efforts  of  330  children  to  describe  an  imaginary 
animal,  and  of  an  attempt  to  gather  statistics  as  to  hypnagogic  images 
from  upward  of  800  children. 

Dawson  :    A   Study   of   Youthful   Degeneracy.     Ihid.^   Vol.   4,   pp. 
221-258  (1896). 

A  careful  study  of  about  60  degenerate  youths  (including  26  boys 
and  26  girls  from  the  state  reform  schools  of  Massachusetts)  as  to 
Vitality,  Head  and  face  configuration,  Anomalies  of  physical  structure, 
Keenness  of  senses,  Intellectual  ability.  Parentage,  and  Environment. 

Hall:  Some  Aspects  of  the  Early  Sense  of  Self.     Am.  Jour,  of  Psy.^ 
Vol.  9,  pp.  351-395  (1898). 

A  study  of  the  growth  and  development  of  self-consciousness  based 
on  questionnaire  returns.  Making  acquaintance  with  hands,  feet,  and 
other  parts  of  the  body,  external  and  internal ;  influence  of  dress 
and  adornment ;  experiences  with  mirrors  ;  various  pet  names ;  childish 
.  conceptions  of  the  soul ;  questionings  of  children  about  their  own  identity, 
present  reality,  etc.;  the  effect  of  social  environment,  beginning  espe- 
cially with  the  mother. 

Psychology  of  Religion. 

Daniels:  The  New  Life:  a  Study  of  Regeneration.     Ihid..,  Vol.  6, 
pp.  61-106  (1893).     (Dissertation.) 

A  study  of  adolescence  in  its  anthropological  and  psychological  as- 
pects, with  special  reference  to  conversion  and  other  religious  experi- 
ences occurring  at  that  period,  the  whole  being  an  effort  to  show  the 
means  by  which  the  fundamental  truths  of  religion  and  theology  may  be 
restated  in  accord  with  science  and  life. 

Leuba  :  A  Study  of  the  Psychology  of  Religious  Phenomena.     Ihid.., 
Vol.  7,  pp.  309-385  (1896).     (Dissertation.) 

Based  upon  noted  cases  of  conversion  found  in  religious  literature,  on 
material  gathered  by  questionnaire  and  in  personal  interviews.  The 
headings  of  the  first  part  are :  The  religious  motive,  Analysis  of  con- 
version. Sense  of  sin,  Self-surrender,  Faith,  Justification,  Joy,  Appear- 
ance of  newness.  The  second  part  treats  of  the  current  doctrines  of 
justification,  faith,  will,  determinism,  and  the  doctrine  of  the  grace  of 
God  as  related  to  the  experiences  described.  An  appendix  contains  a 
number  of  the  cases  in  full. 


Psychology.  135 

Stakbuck:  a  Study  of  Conversion.  Ihid.^  Vol.  8,  pp.  268-308 
(1897). 

Contributions  to  the  Psychology  of  Religion :  Some  Aspects  of 
Religious  Growth.   Ibid.,  Yol.  9,  pp.  70-124(1897).   (Dissertation.) 

The  first  paper  is  a  study  of  sudden  conversions ;  the  second  of  more 
gradual  changes  of  a  similar  character.  Both  are  based  almost  exclu- 
sively on  questionnaire  returns ;  the  first  on  137  cases,  the  second  on  195. 
The  topics  in  the  first  paper  are :  Age  of  conversion,  Motives  and  forces 
leading  to  conversions,  Experiences  preceding  conversion,  The  change 
itself.  Post-conversion  phenomena,  Other  experiences  similar  to  conver- 
sion, General  view  of  conversion.  Those  of  the  second  paper  are: 
Statistics  of  material,  Adolescent  phenomena.  The  period  of  reconstruc- 
tion. External  influences.  Cases  without  marked  stages  of  growth,  Adult 
religious  consciousness,  Ideals,  Significance  of  the  facts. 

Leuba:  The  Psycho-physiology  of  the  Moral  Imperative.  Ibid., 
Vol.  8,  pp.  528-559  (1897). 

An  analysis  of  the  phenomena  of  conscience,  together  with  argument 
to  show  that  the  "  moral  imperative  "  is  the  psychical  correlate  of  cer- 
tain activities  of  the  cerebro-spinal  system  (taken  as  the  neural  basis  of 
the  life  of  relation)  as  opposed  to  activities  of  the  sympathetic  system 
(taken  as  the  neural  basis  of  the  vegetative  and  emotional  life). 

Philosophy  and  Criticism. 

KiKKPATRiCK :  Observations  on  College  Seniors  and  Electives  in 
Psychological  Subjects.     Ibid.,  Vol.  3,  pp.  168-173  (1890). 

A  study  of  questionnaire  returns  from  college  seniors  as  to  their  rea- 
sons for  studying  philosophical  and  psychological  subjects,  benefit  gained, 
authors  most  impressive,  and  special  topics  found  most  interesting. 

Hall:  Contemporary  Psychologists.  I.,  Prof.  EduardZeller.  Ibid., 
Vol.  4,  pp.  156-175  (1891). 

An  account  of  the  life  and  writings  of  Zeller. 

Fkaser  :  Visualization  as  a  Chief  Source  of  the  Psychology  of 
Hobbes,  Locke,  Berkeley,  and  Hume.  Ibid.,  Vol.  4,  pp.  230-247 
(1891). 

The  Psychological  Foundation  of  Natural  Realism.  Ibid.,  Vol. 
4,  pp.  429-450  (1892). 


136  Department  of 

The  Psychological  Basis  of  Hegelism.  Ihid,^  Vol.  5,  pp.  472- 
495  (1893). 

These  papers  are  the  result  of  an  effort  toward  a  "  psychology  of  phi- 
losophy." The  fu-st  two  trace  the  influence  of  concepts  derived  from 
vision  and  from  touch  on  the  philosophic  schools  in  question,  and  the 
third  the  influence  of  those  derived  from  galvanism. 

Bailey  :  Ejective  Philosophy.     Ihid.,  Vol.  5,  pp.  465-471  (1893). 

An  attempt  to  describe  briefly  the  philosophical  "signs  of  the 
times." 

Leuba  :  National  Destruction  and  Construction  in  France  as  seen  in 
Modern  Literature  and  in  the  Neo-Christian  Movement.  Ihid.^ 
Vol.  5,  pp.  496-539  (1893). 

A  review  of  these  topics  under  the  following  heads :  Artist  sensual- 
ists, The  quest  for  new  sensations,  Nihilism  and  pessimism,  School  of  the 
decadents,  Literary  critics,  Chronicles,  The  tormented,  The  Neo-Chris- 
tian movement. 

Allin  :  The  "  Recognition-theory  "  of  Perception.  Ihid.^  Vol.  7,  pp. 
237-248  (1896). 

Recognition.     lUd.,  Vol.  7,  pp.  249-273  (1896). 

The  first  paper  is  a  critique  of  a  theory  of  perception  widely  held  in 
the  past  and  present ;  the  second  is  an  analytical,  critical,  and  expository 
account  of  the  mental  experience  of  recognition. 

Mental  and  Physical  Peculiarities. 

Scripture:  Arithmetical  Prodigies.     Ilid.^  Vol.  4,  pp.  1-59  (1891). 

Accounts  of  a  large  number  of  phenomenal  calculators  collected  from 
widely  scattered  sources ;  analysis  and  discussion  of  their  mental  pecu- 
liarities, and  pedagogical  inferences. 

Krohjst  :  Pseudo-chromsesthesia,  or  the  Association  of  Colors  with 
Words,  Letters,  and  Sounds.     lUd.,  Vol.  5,  pp.  20-41  (1892). 

A  summary  of  literature  with  presentation  of  several  new  cases,  and  a 
discussion  of  the  theory  of  the  phenomenon,  followed  by  a  bibliography, 

LiNDLEY :  A  Preliminar}'  Study  of  some  of  the  Motor  Phenomena  of 
Mental  Effort.     Ihid.,  Vol.  7,  pp.  491-517  (1896). 

A  study,  on  the  basis  of  a  questionnaire  and  special  tests,  of  the  tricks 
and  peculiarities  of  movement  and  posture  that  accompany  mental  effort. 


Psychology.  137 

LiNDLEY  AND  PARTRIDGE  :  Some  Mental  Automatisms.    Pedagogical 
Seminary,  Vol.  5,  pp.  41-60  (1897). 

A  qxiestionnaire  study  of  495  cases  of  such  mental  automatisms  as  the 
avoidance  of  stepping  on  cracks,  counting  objects  unnecessarily,  group- 
ing objects  like  small  patterns  in  wall  paper  into  regular  figures,  and 
the  picking  out  the  middle  one  of  rows  of  objects. 

Phillips  :  Genesis  of  Number  Forms.    Am.  Jour,  of  Psy.^  Vol.  8, 
pp.  506-527  (1897). 

A  study,  based  on  over  2000  cases  (974  school  children,  and  nearly 
700  normal  school  pupils  and  adults  personally  questioned),  showing  the 
almost  universal  presence  of  number  forms,  though  often  in  very  rudi- 
mentary condition. 

COLEGRO VE :  Individual  Memories.    Ibid.,  Vol.  10,  pp.  228-255  (1899) . 
(Dissertation.) 

The  paper  is  a  study  of  some  sixteen  hundred  replies  to  a  question- 
naire on  earliest  memories,  period  of  life  best  remembered,  forgetful- 
ness  and  false  memories,  aids  to  memory,  etc.  This  paper  is  an  extract 
from  a  more  extended  work  on  memory  in  general. 

Emotion. 

Hall  :  A  Study  of  Fears.     lUd.,  Vol.  8,  pp.  147-249  (1897). 

Discussion  of  the  chief  fears  of  seventeen  hundred  people  mostly 
under  twenty-three  years  of  age,  together  with  description  of  methods 
used  in  reducing  the  original  reports  for  general  treatment.  Fears  of 
high  places  and  falling,  of  losing  orientation,  of  being  shut  in,  of  water, 
of  wind,  of  celestial  objects,  of  fire,  of  darkness ;  dream  fears ;  shock ; 
fears  of  thunder,  of  animals,  of  eyes,  of  teeth,  of  fur,  of  feathers ; 
special  fears  of  persons,  of  solitude,  of  death,  of  diseases ;  moral  and 
religious  fears ;  fear  of  the  end  of  the  world,  of  ghosts ;  morbid  fears ; 
school  fears ;  and  the  repression  of  fears,  —  are  all  treated  in  separate 
sections. 

Hall  and  Allin:  The  Psychology  of  Tickling,  Laughing,  and  the 
Comic.     Ibid.,  Vol.  9,  pp.  1-41  (1897). 

A  study  based  upon  about  seven  hundred  questionnaire  returns.  The 
following  rubrics  are  treated:  The  Physical  act  of  laughing.  Tickling, 
Animals  and  their  acts,  Eecovery  from  slight  fear.  Laughter  at  calamity, 
Practical  jokes.  Caricature,  Wit,  Laughter  at  what  is  forbidden  or  secret, 
at  the  naive  and  unconscious,  Animal  laughter,  Miscellaneous  items,  and 
Notes  on  literature. 


138  Department  of 

Hall  :  A  Study  of  Anger.     Ibid.,  Vol.  10,  pp.  516-591  (1899). 

A  general  summary  of  very  widely  gathered  literary  material,  followed 
by  a  discussion  of  over  two  thousand  questionnaire  returns ;  General 
descriptions  of  the  state,  Causes  (with  many  sub-heads).  Subjective 
variations.  Physical  manifestations  (with  many  sub-heads),  Anger  at 
inanimate  and  insentient  objects.  Venting  anger.  Reaction,  Control, 
Treatment,  Miscellaneous  aspects. 

Miscellaneous  Topics. 

MacDonald  :  Ethics  as  Applied  to  Criminology.  Journal  of  Mental 
Science,  Vol.  37,  pp.  10-16  (1891). 

Criminal  Aristocracy,   or   the    Maffia.      Medico-Legal   Journal, 
Vol.  9,  pp.  21-26  (1891). 
Le  Rossignol  :   The  Training  of  Animals.     Am.  Jour,  of  Psy.,  Vol. 
5,  pp.  205-213  (1892). 

A  review  of  literature  on  the  subject. 

Kkohn  :  Facilities  in  Experimental  Psychology  at  Various  German 
Universities.  Ibid.,  Vol.  4,  pp.  585-594  (1892);  Vol.  5,  pp.  282- 
284  (1892). 

Notes  on  Heidelberg,  Strasburg,  Zurich,  Freiburg,  Munich,  Prag,  Ber- 
lin, Leipzig,  Halle,  Jena,  Bonn,  and  Gottingen. 

Lemon:  Psychic  Effects  of  the  Weather.  Ibid.,  Vol.  6,  pp.  277-279 
(1894). 

A  preliminary  note  on  the  general  question. 

Scott  :  Sex  and  Art.     Ibid.,  Vol.  7,  pp.  153-226  (1896). 

The  study  traces  the  higher  enthusiasms  of  art  and  religion,  as  well  as 
the  passions  of  sex,  to  the  "  fundamental  quality  of  erethism  found  in 
every  animal  cell."  Beginning  with  erethism,  the  following  topics  are 
discussed :  Specialization  among  cells,  Separation  of  the  sexes,  Radia- 
tion, Selection,  Combat,  Courting,  Fear  and  anger.  Sex  and  care  for 
young,  The  aesthetic  capacity.  Courting  instinct  in  the  lower  races, 
Tattooing,  Clothing,  Shame,  Jealousy  and  fear.  Symbolism  and  fetich- 
ism,  Phallicism,  Modern  phallicism,  General  features  and  laws  of  court- 
ing. Degeneration,  Perversion,  Ecstasy,  Esthetics,  Conclusion. 

Scott  :  Old  Age  and  Death.  Ibid.,  Vol.  8,  pp.  67-122  (1896).  (Dis- 
sertation.) 

Old  age  and  death  treated  from  biological  and  physiological  stand- 
points, together  with  discussion  of  226  returns  to  a  questionnaire  designed 


Psychology.  139 

to  bring  out   the  ideas  of  young  people  and  others  with  regard  to  the 
aged,  to  death,  and  to  a  future  life. 

Partridge  :  Blushing.  Pedagogical  Seminary^  Vol.  4,  pp.  387-394 
(1897). 

A  questionnaire  study  (120  cases,  all  normal  school  pupils):  Objective 
and  subjective  aspects.  After-effects,  Physiology,  Psychology,  Blushing 
and  sex. 

Partridge:  Second  Breath.     Ihid.,  Vol.  4,  pp.  372-381  (1897). 

A  study  based  upon  about  two  hundred  questionnaire  returns.  The 
following  are  the  headings :  Physical  second  breath,  Mental  second 
breath,  Over-play  and  abandon  in  children,  Reaction,  Physiology  of 
second  breath. 

LiNDLEY :  A  Study  of  Puzzles  with  Special  Reference  to  the  Psy- 
chology of  Mental  Adaptation.  Am.  Jour,  of  Psy.^  Vol.  8,  pp. 
431-493  (1897).     (Dissertation.) 

The  subject  is  introduced  by  a  consideration  of  the  biology  and  psy- 
chology of  play  in  general,  followed  by  the  classification  of  puzzles. 
The  time  and  conditions  of  greatest  interest  in  puzzles  are  treated  on  the 
basis  of  questionnaire  returns.  This  is  followed  by  a  report  of  extended 
experiments  made  upon  school  children  to  discover  their  growth  in  abil- 
ity to  deal  with  the  difficulties  presented  by  puzzles. 

Kline:  The  Migratory  Impulse  vs.  Love  of  Home.  Ibid.,  Vol.  10, 
pp.  1-81  (1898).     (Dissertation.) 

A  biological  and  psychological  study  combining  the  results  of  experi- 
ments upon  animals  with  those  of  a  questionnaire.  Such  topics  as  the 
Influence  of  temperature,  Spring  fever.  Migrations  of  wild  and  domestic 
animals  and  of  man,  Wandering  tendency  in  men,  women,  and  children, 
Love  of  home,  and  homesickness,  are  treated. 

Qfantz  :  Dendro-psychoses.    Ibid.,  Vol.  9,  pp.  449-506  (1898). 

A  study  on  material  gathered  from  biology,  anthropology,  and  ques- 
tionnaire returns  of  the  psychic  influence  of  experiences  with  trees. 
Biological  evidence  of  man's  descent  from  arboreal  ancestors.  Psychical 
reverberations  from  ancestral  experience.  Tree  worship,  The  life  tree, 
The  tree  in  folk-medicine.  The  tree  in  child  life.  The  tree  in  poetry. 

Bolton,  F.  E.  :  Hydro-psychoses.  Ibid.,  Vol.  10,  pp.  171-227 
(1899).     (Dissertation.) 

A  study,  similar  to  the  last,  on  the  psychic  effects  of  experiences  with 
water :  Evidences  of  man's  pelagic  ancestry,  Origin  of  animal  life,  Ani- 


140  Departme7it  of 

mal  retrogression  to  aquatic  life,  Water  in  primitive  conceptions  of  life, 
in  philosophical  speculation,  Sacred  waters.  Water  deities,  Lustrations 
and  ceremonial  purifications  by  water,  Water  in  literature,  Feelings  of 
people  at  present  toward  water. 

GODDARD :  The  Effects   of   Mind,  on  Body  as   evidenced   by   Faith 
Cures.     Ihid.,  Vol.  10,  pp.  431-502  (1899).     (Dissertation.) 

"■  Christian  Science,"  "  Divine  Healing,"  hypnotism  and  other  forms 
of  mental  treatment  of  disease  are  briefly  considered ;  and  "  Mental  Sci- 
ence," taken  as  a  type,  is  treated  fully  from  data  gathered  by  extended 
correspondence  and  from  hospital  records.  In  the  remainder  of  the 
paper  the  following  topics  appear :  Positive  testimony  of  the  influence 
of  mind  on  disease.  Failures  in  the  practice  of  mental  therapeutics. 
Hypnotism  as  a  therapeutic  agent,  Theory  of  mental  therapeutics.  Psy- 
chological problems  suggested.  Resume  and  conclusions. 

Street  :  A  Genetic   Study  of   Immortality.     Pedagogical  Seminary^ 
Vol.  6,  pp.  267-313  (1899).     (Dissertation.) 

A  study  of  the  origin  and  characteristics  of  ideas  of  the  soul,  im- 
mortality, heaven,  and  a  future  life,  made  on  the  basis  of  the  reports 
of  the  thoughts  of  deaf  mutes  before  training,  on  about  five  hundred 
replies  to  a  questionnaire,  and  on  other  material.  Biological,  psychologi- 
cal, and  moral  aspects  of  the  belief  in  immortality  are  also  considered. 

Besides  the  studies  of  these  lists,  which  have  been  j)rinted,  a  number 
more  have  been  made  and  are  in  the  hands  of  the  instructors  practically 
ready  for  publication.  Others  still  have  been  made  and  the  data  sub- 
mitted without  complete  writing  out ;  a  good  part  of  these  will  ultimately 
be  made  use  of  either  in  themselves  or  as  the  basis  for  further  research 
along  the  same  lines. 


After  this  outline  of  work  done  in  the  past,  a  few  words  may  be  per- 
mitted with  reference  to  the  future  of  the  department.  This,  like  its 
past,  must  be  closely  connected  with  the  general  progress  of  ]3sychological 
science,  and  the  question  naturally  becomes  that  of  the  directions  in  which 
progress  may  be  most  reasonably  expected.  Let  me  begin,  as  before,  with 
the  laboratory. 

It  seems  to  me  that  the  two  lines  of  greatest  promise,  conceding  readily 


Psychology.  141 

the  importance  of  continuing  research  along  lines  already  undertaken,  are 
those  of  comparative  and  of  individual  psychology.  Work  has  already 
been  begun  in  both  fields.  Especially  in  comparative  psychology  much 
has  already  been  done  by  the  biologists,  but  much  remains  yet  to  be  done. 
There  is  surprisingly  little  accurate  knovv^ledge  of  the  mental  life  of  even 
the  commonest  animals  ;  there  are  many  anecdotes,  but  not  many  reliable 
observations,  and  very  few  experiments.  In  this  field  lie  the  questions  of 
instinct  and  heredity,  belonging  alike  to  psychology  and  biology,  to  which 
run  back  so  many  of  the  most  fundamental  and  practical  of  even  strictly 
psychological  questions.  Much  may  also  be  expected  from  the  full  intro- 
duction into  psychology  of  the  comparative  method  which  has  so  broad- 
ened and  enriched  other  sciences  in  which  it  has  been  applied.  The 
conception  of  mind,  as  of  something  not  narrowly  human  or  confined  to  a 
few  higher  animals,  but  as  in  some  sort  present  in  all  animals,  even  the 
lowest,  with  a  history  as  long  as  evolution,  opens  up  vistas  to  which  psy- 
chologists have  been  too  little  accustomed.  Much  surely  is  to  be  expected 
from  this  closer  alliance  of  psychology  with  biology. 

While  the  theoretical  interest  of  comparative  psychology  is  thus 
hardly  to  be  overestimated,  the  practical  interest  of  the  efforts  toward  an 
individual  psychology  is  hardly  less  important.  We  know  something 
about  the  mental  differences  of  our  fellow-men,  but  we  know  very  little 
about  them  in  a  scientific  way.  What  underlies  temperament?  What 
are  the  laws  of  the  growth  of  character?  Why  do  some  pupils  do  well 
with  some  teachers  and  not  with  others  ?  What  is  the  best  treatment  for 
reform  school  boys  ?  How  shall  one  deal  with  exceptional  and  peculiar 
children  in  the  family?  Individual  psychology  ought  to  answer  such 
questions  as  these,  and  many  others.  It  is  clear,  of  course,  that  many  of 
these  questions  extend  far  beyond  the  possibilities  of  the  laboratory,  but 
the  methods  and  standpoint  and  training  of  the  laboratory  will  play  no 
small  part  in  their  final  solution,  and  justify  attacking  them  from  that 
side. 

Closely  connected  with  individual  psychology,  but  lying  a  little  fur- 
ther from  the  laboratory,  is  another  field  which  might  be  called  the 
"  psychology  of  the  permanent  apperceptive  groups  "  —  the  study  of  the 
mental  attitudes,  that  is,  that  result  from  the  fundamental  experiences  of 
life,  a  study  of  appercei)tion  which  does  not  stop  at  demonstrating  the 
fact  of  mental  habit,  but  goes  on  to  investigate  the  effect  of  one  sort  of 
mental  habit  upon  the  rest  ;  how,  for  example,  the  fact  of  fatherhood  or 


142  Department  of 

a  severe  sickness  may  alter  character  distinctly  and  permanently.  These 
topics  have  not  been  neglected,  but  many  questions  remain  that  would 
well  repay  the  worker  of  proper  equipment  and  insight.  Coordinate  with 
these  are  the  study  of  the  more  complex  emotions,  of  religion  and  of 
aesthetics,  all  of  which  promise  much  and  should  have  an  important  place 
in  a  psychological  department  as  a  counterweight  to  the  laboratory.  It 
is  on  the  data  obtained  from  the  study  of  these  topics  and  those  of  the 
last  group,  with  others  like  them,  that  true  mental  and  moral  hygiene 
must  rest.     Fortunately,  here  also  we  have  beginnings. 

Beyond  these  again,  there  are  topics  of  great  popular  interest,  like 
those  of  Christian  science  and  psychical  research,  upon  which  the  lay- 
man has  a  right  to  ask  an  expert  opinion  from  science,  and  on  which 
psychology,  after  careful  investigation,  can  and  ought  to  speak. 

What  any  particular  department  of  psychology  can  do  in  realizing 
these  promises  of  the  future,  must  depend  upon  the  resources  in  men  and 
materials  that  it  can  command.  Work  in  comparative  psychology  can  be 
begun  at  once  wherever  suitable  accommodations  can  be  provided  for  the 
animals, — proper  housing,  cages,  aquaria,  and  such  attendance  as  shall 
insure  the  health  and  happiness  of  the  animals,  which  are  essential  factors 
in  any  reliable  study  of  their  behavior,  —  and  a  properly  qualified  observer 
can  be  secured.  The  first  of  these  requirements  is  easier  to  fill  at  present 
than  the  second,  for  as  yet  too  few  persons  have  equipped  themselves  both 
as  psychologists  and  naturalists,  but  this  lack  will  not  long  exist  if  the 
subject  is  taken  up  in  earnest.  For  the  portion  of  individual  psychology 
that  comes  within  the  scope  of  the  laboratory,  there  is  need  of  new  instru- 
ments of  at  least  a  relative  precision,  many  of  which  must  yet  be  devised 
or  slowly  perfected  by  trial  and  failure,  which  involves  a  liberal  subsidy. 
For  any  of  the  more  general  problems  mentioned,  the  first  requisite  is 
men  of  proper  natural  equipment  and  training.  Not  every  man  of  learn- 
ing is  fitted  to  handle  them,  and  those  devoted  to  them  must  not  be  so 
much  taken  up  with  the  routine  and  responsibility  of  elementary  teaching, 
that  they  lack  the  time  and  spirit  for  ardent  research.  And  these  men, 
once  secured,  must  be  liberally  supplied  with  such  help  in  the  way  of 
books  and  other  materials  as  they  need.  Of  these  three  things, —  quarters 
for  comparative  psychology,  apparatus  for  individual  psychology,  and  an 
enlargement  of  the  staff,  —  the  last  is,  in  all  ways,  by  far  the  most  impor- 
tant. Competent  and  enthusiastic  investigators  can  work  with  inadequate 
facilities,  but  no  facilities  can  take  the  place  of  the  men  or  of  the  freedom 


Psychology.  143 

from  routine  teaching.  The  Clark  department  has  already  made  such 
efforts  in  all  these  lines  as  its  opportunities  have  permitted.  Its  ten  years' 
history  justifies  the  prophecy  that,  with  enlarged  opportunities,  it  would 
make  more  than  commensurate  return  in  an  increase  of  the  advanced 
teaching  and  research  for  which  it  was  originally  organized. 


PSYCHO-PATHOLOGY. 

By  Adolf  Meyer. 

It  is  hardly  necessary  to  insist  to-day  on  the  remarkably  suggestive 
influence  which  pathology  has  had  on  the  biology  of  man,  and  especially 
on  psychology.  Many  of  the  most  fundamental  changes  in  psychology 
are  directly  traceable  to  problems  furnished  by  the  study  of  abnormal 
life,  clinical  and  post-mortem  pathology,  and  experimental  reproduction 
of  diseases  and  of  symptom-complexes.  Under  these  conditions  it  is 
evident  that  the  curriculum  of  a  psychologist,  and  of  biologists  generally, 
is  quite  incomplete  without,  at  least,  some  touch  with  results  and  problems 
of  general  pathology,  and  more  especially  of  neuro-  and  psycho-pathology. 

Starting  from  the  experience  that  certain  types  of  psycho-pathology 
lead  very  promptly  into  paths  which  have  nothing  to  do  with  biology, 
and  put  themselves  directly  on  pre-biological  traditions,  it  was  considered 
best  to  develop  a  course  which  would  begin  with  the  principles  of  general 
pathology,  the  abnormalities  of  the  most  general  biological  factors,  i.e. 
with  a  chapter  properly  belonging  to  any  general  biology.  In  this 
field,  the  experience  in  the  domain  of  neurology  and  of  psychiatry 
would  have  to  be  worked  up  more  carefully,  as  far  as  possible  in  constant 
touch  with  the  broader  biological  concepts. 

Medicine,  barely  deserving  the  attribute  of  an  applied  science,  is 
not  rich  in  literature  breathing  the  biological  spirit.  To  a  great  extent 
it  stands  on  a  pre-biological,  materialistic  standpoint,  and  the  orthodox 
practitioner  of  medicine  is  usually  anxious  to  keep  to  materialism  and 
to  profess  ignorance  of  the  psychological  aspect ;  and,  again,  many  of 
those  who  look  upon  the  psychological  manifestations  in  their  patients 
very  rapidly  acquire  one  of  the  traditional  exclusive  standpoints,  danger- 
ously near  certain  mystical  concepts.  The  psychology  of  hypnotism, 
of  hysteria,  even  that  of  aphasia,  give  good  instances  of  such  tendencies. 
It  is  consequently  desirable  to  build  up  a  course  from  the  elementary 
to  the  more  difficult,  and  starting  from  the  least  contested  foundations 
to  proceed  to  the  less  comprehensible  points. 

144 


Psycho-Pathology.  145 

The  plan  outlined  in  the  lectures  and  clinics  of  the  spring  of  1897 
gives  an  idea  of  the  work. 

The  course  during  the  year  covered  the  following  ground  :  — 

1.  Introductory  remarks  on  general  biological  conceptions.  The  gen- 
eral biological  principles  applied  to  the  study  of  abnormal  life.  Relation 
between  neurology  and  psychology,  neuro-pathology  and  psychiatry,  neuro- 
logical and  psychical  phenomena  from  the  biological  standpoint.  Appli- 
cation of  the  point  of  view  to  alcoholic  intoxication  and  to  several  forms 
of  mental  disease.  Demonstration  :  Cases  of  Febrile  Delirium,  General 
Paralysis,  Catatonia,  and  Idiocy. 

2.  Review  of  the  general  pathology  on  the  grovmd  of  the  aspect- 
hypothesis.  The  terms  "  disease,"  "  residual,"  "  defective  formation,"  and 
"defective  Anlage."  Clinical  and  post-mortem  pathology  and  their  share 
in  general  pathology.  Only  clinical  pathology  furnishes  data  on  the  psy- 
chological and  physiological  side.  Plan  of  clinical  study.  Anatomical 
study.  Our  knowledge  of  the  macroscopic  and  microscopic  lesions 
of  the  nervous  system  and  the  underlying  pathological  processes, 
defective  growth  and  nutrition,  intoxication,  abnormal  function.  Local 
disorders  :  Abnormal  circulation,  local  intoxications,  traumatic  disorders, 
over  activity,  perverted  function.  Demonstration  of  abnormal  brains  and 
histological  changes. 

3.  The  general  plan  of  the  nervous  system  and  illustrations  of 
diseases  of  the  various  parts  (levels).  The  neural  tube;  the  segmentary 
arrangement  and  the  elements  of  the  segments  within  the  lowest  level. 
The  middle  level  apparatus  —  cerebellum,  midbrain,  and  forebrain,  and 
their  afferent  and  efferent  connections.  Demonstrations  :  (1)  Traumatic 
paralysis  of  the  nervus  peroneus.  (2)  Infantile  paralysis.  (3)  Cases  of 
hemiplegia.  (4)  Lead  paralysis  (Remak  type).  (5)  Alcoholneuritis. 
(6)    Locomotor  ataxia. 

4.  The  principles  of  localization.  The  meaning  of  the  connections 
of  neurones  by  numerous  collaterals,  of  the  "  interruptions  of  the  tracts 
by  gray  matter,"  of  the  term  "centre."  Description  of  the  most 
important  "centres,"  the  lesions  of  the  apparatus  of  mimic  movements, 
the  sensorimotor  areas,  the  principal  "  sensory "  projection  fields.  An 
outline  of  the  principles  of  aphasia  and  its  forms,  of  hemianopsia. 
Highest  level  symptoms.  Demonstration  :  Hemiplegia  with  hemianop- 
sia ;  two  cases  of  hemiplegia  with  motor  aphasia ;  one  case  of  sensory 
aphasia.     Reference  to  a  case  of  Brown-Sequard  paralysis. 


146  Psyclio-Pathology. 

5.  General  outline  of  mental  diseases.  Explanation  of  Kraepelin's 
classification.  Illustration  of  a  paradigm  of  mental  disease :  General 
Paralysis,  its  etiolog}^  symptomatology,  and  principal  types.  Demonstra- 
tion of  six  cases. 

6.  Toxic  psychoses  and  psychoses  of  disturbed  metabolism.  Sum- 
mary of  the  data  of  psycho-physiological  study  of  fatigue  and  intoxication 
furnished  by  the  school  of  Kraepelin.  Review  of  the  methods  and  the 
results.  Application  to  the  clinical  problems.  Demonstration  :  Delirium 
Tremens,  Subacute  Alcoholic  Insanity.  Cretinism.  Dementia  Precox  and 
Catatonia. 

7.  Periodic  Insanity  compared  with  the  types  of  Verbloedungs- 
processe.  Demonstration  of  further  types  of  Catatonia  and  of  Periodic 
Insanity;  "Acute  Mania,"  "Acute  Melancholia." 

8.  Short  sketch  of  Senile  Dementia  and  demonstration  of  a  case. 
Constitutional  psychoses.  Resume  of  the  methods  and  aims  of  individual 
psychology  (Cattell,  Miinsterberg,  Jastrow,  Kraepelin,  Gilbert,  Binet  et 
Henri,  Guicciardi  and  Ferrari).  Value  of  "types"  of  character  or 
constitution.  Their  formation.  Dominant  ideas.  Mysophobia  as  a 
type  of  Neurosis  of  Fear.     Development  of  Paranoia  ;  cases  of  Paranoia. 

In  the  spring  of  1896  a  similar  course  of  demonstrations  had  been 
given  (see  the  outline,  American  Journal  of  Psychology,  April,  1896, 
Vol.  7,  pp.  449-450).  In  the  spring  of  1898  only  one  lecture  was  possible 
(on  the  methods  of  individual  psychology,  especially  Kraepelin's  work) 
and  a  short  course  of  four  clinics  in  the  spring  of  1899.  The  desire  to 
extend  the  studies  into  research  work  has  remained  unfulfilled.  Several 
attempts  failed  because  the  possibilities  for  such  work  were  not  mature, 
neither  on  the  side  of  the  hospital  nor  on  the  part  of  the  University. 

The  general  principles  of  the  work  at  Clark  University  tend  toward 
the  education  of  workers.  So  far  the  sub-department  of  psycho-pathology 
has  been  purely  didactic,  covered  by  the  lectures  of  President  Hall,  on 
the  topics  which  have  specially  attracted  psychology,  e.g.^  border-line 
phenomena,  as  seen  in  neurotic  people,  prodigies,  and  geniuses ;  defec- 
tives, such  as  the  blind,  deaf,  criminal,  idiotic ;  mental  and  nervous 
diseases,  epilepsy,  phobias,  neurasthenia,  hysteria ;  morbid  modifications 
of  will,  personality,  emotion,  etc.,  and  by  the  above  attempt  at  giving  a 
course  with  clinics  based  on  general  pathology. 

The  research  work  along  these  lines  depends  on  two  important  condi- 
tions.     For  systematic  work  the  organization  of  a  clinic  is  necessary, 


Psyclio-Patliology .  147 

and  on  the  part  of  the  worker  a  fair  knowledge  of  general  and  special 
pathology  (in  its  broadest  sense  —  the  knowledge  of  abnormal  life,  not 
merely  pathological  anatomy  and  bacteriology)  is  an  absolute  pre- 
requisite. 

A  training  in  general  and  special  pathology  on  the  ground  of  a 
complete  course  of  biology  must  be  regarded  as  an  absolutely  necessary 
pre-requisite  for  research  in  psycho-pathology.  Whether  most  courses 
of  medicine  offer  what  is  needed,  and  whether  a  medical  education 
should  be  required,  is  a  matter  of  some  doubt ;  since  much  of  the  ordinary 
medical  course  is  business  training  rather  than  work  in  pathology  in 
the  true  sense  of  the  word,  leaving  out  almost  intentionally  the  broader 
aspects  which  we  have  to  require  more  especially  for  research  in  our 
lines ;  and  most  of  the  medical  courses  are  so  overburdened  that  the 
training  in  the  history  of  human  thought  and  philosophical  criticism 
is  completely  crowded  out,  and  this  important  safety-valve  and  balancing 
apparatus  is  almost  missing  in  the  medical  curriculum. 

The  other  point,  the  creation  of  clinical  possibilities,  is  not  less 
difficult.  Our  attempt  at  the  Worcester  Insane  Hospital  has  hardly 
matured  sufficiently  to  allow  of  much  research  work.  The  work  which 
forms  the  foundation  of  research  must  be  done  first,  and  the  reorganiza- 
tion begun  in  1896  is  only  just  beginning  to  furnish  the  material  for 
some  studies  suggested  by  Dr.  Sanford,  and  some  investigations  on 
more  closely  psychiatric  questions. 

The  study  of  the  most  protracted  disorders  of  human  life  requires 
such  a  patient  spirit  of  work  and  an  atmosphere  of  such  tenacious 
adherence  to  solid  working  principles,  that  the  predilection  for  fads 
and  the  haste  for  results  are  nowhere  more  lamentable.  Should  it  be 
the  good  fortune  of  this  department  to  get  strengthened  by  the  State, 
as  well  as  by  the  University,  a  psychiatric  clinic  and  research-station 
might  grow  up.  Efforts  of  this  character  are  being  made  in  New  York 
by  an  institute  independent  of  the  hospitals.  Our  plan  is  rather  to  develop 
the  research-station  on  the  basis  of  the  clinical  work.  The  constant  con- 
tact with  a  field  of  experience  such  as  a  clinic  offers  furnishes  the  safest 
working  basis  and  prevents  one  from  running  away  with  hasty  specula- 
tion derived  from  too  limited  a  number  of  facts.  The  best  field  for 
getting  problems  for  work  is  that  of  actual  observation,  such  as  a  clinic 
only  can  afford.  To  pick  out  curiosities  merely  will  never  lead  to  a 
psycho-pathology  worth  its  name. 


ANTHKOPOLOGY. 

By  Alexander  Francis  Chamberlain. 

The  history  of  the  Department  of  Anthropology  at  Clark  University 
forms  an  important  chapter  in  the  history  of  the  study  of  anthropology  in 
America,  since  it  was  the  first  educational  institution  to  distinctly  recog- 
nize anthropology  as  a  subject  of  graduate  study  leading  to  the  degree  of 
Doctor  of  Philosophy. 

The  first  official  announcement  of  the  University,  published  in  May, 
1889,  included,  under  the  work  to  be  undertaken  in  the  Department  of 
Psychology,  the  following  subjects :  "  The  Psychology  of  Language ; 
Myth,  Custom,  and  Belief  anthropologically  considered."  With  the 
opening  of  the  academic  year,  anthropology  was  established  as  Section 
C  of  the  Department  of  Psychology,  and  a  laboratory  and  departmental 
library  provided,  with  proper  facilities  for  original  investigation  and 
research.  The  laboratory  contained  crania  for  practical  study,  necessary 
craniographic  and  craniometric  instruments,  together  with  the  usual  tools 
of  the  anthropologist  working  in  the  field. 

The  library  of  the  University,  besides  a  special  anthropological  collec- 
tion, contains  a  very  complete  selection  of  the  literature  on  applied  ethics 
(criminology),  embracing  the  chief  works  of  the  English,  Italian,  French, 
and  German  writers.  In  the  psychological  library  will  be  found  also 
many  works  relating  to  the  subjects  which  anthropology  and  psychology 
treat  of  in  common. 

In  1889  Dr.  Franz  Boas  (now  Professor  of  Anthropology  at  Columbia 
University,  New  York),  a  graduate  of  the  University  of  Kiel,  who  was 
already  well  known  through  his  researches  among  the  Eskimo  of  Baffin 
Land  and  the  Indians  of  Alaska  and  British  Columbia,  was  appointed 
Docent  in  Anthropology,  which  position  he  held  until  the  close  of  the 
academic  year,  1891-92,  when  he  assumed  the  duties  of  director  of  the 
sub-department  of  physical  anthropology  at  the  World's  Columbian 
Exposition,  taking  with  him  his  fine  collection  of  crania.     At  the  Uni- 

148 


Anthropology.  149 

versity  Dr.  Boas  continued  his  studies  of  the  anthropology  of  the 
Northwest  Coast,  paying  especial  attention  to  a  monograph  on  "  The 
Mythologies  of  the  North  Pacific  Coast,"  which  he  prepared  for  pub- 
lication, and  to  osteological  studies  of  the  material  collected  during  his 
several  journeys. 

In  the  summer  of  1890  Dr.  Boas  was  engaged  in  investigating  the 
anthropology,  ethnology,  and  linguistics  of  the  Indian  tribes  of  the  coast 
of  British  Columbia,  under  the  auspices  of  the  British  Association  for 
the  Advancement  of  Science.  His  report,  presented  to  the  Leeds  meeting 
in  1891,  treated  of  the  customs  and  beliefs  of  the  Bella  Coola,  who  were 
shown  to  be  of  Salishan  stock,  besides  containing  a  general  review  of  the 
physical  characteristics  of  the  Indians  of  the  North  Pacific  coast,  with  a 
discussion  of  the  problem  of  mixed  races.  Studies  of  the  Chemakum  and 
Chinook  languages  were  also  continued  and  articles  prepared  for  publica- 
tion. Early  in  1890,  the  approval  of  the  school  authorities  having  been 
obtained,  an  extensive  series  of  anthropological  measurements  was  begun 
in  the  schools  of  the  city  of  Worcester,  and  carried  to  successful  comple- 
tion. Preparations  were  also  made  for  the  inauguration  of  similar 
investigations  in  other  parts  of  the  Union  and  in  Canada.  These 
measurements  were  undertaken  with  the  object  of  studying  the  growth 
of  children  as  influenced  by  varying  conditions.  The  investigations  in 
Worcester  were  carried  on  by  Dr.  Boas,  with  the  assistance  of  the  follow- 
ing members  of  the  University  :  Dr.  G.  M.  West,  Mr.  A.  F.  Chamberlain, 
Mr.  T.  L.  Bolton,  Mr.  J.  F.  Reigart.  In  the  spring  of  1891  preparations 
were  made  for  extensive  anthropological  measurements  of  the  American 
Indians,  under  the  auspices  of  the  World's  Columbian  Exposition,  Dr. 
Boas  being  placed  in  charge  of  the  sub-department  of  physical  anthro- 
pology. In  prosecution  of  these  investigations,  the  following  students  of 
the  University,  trained  in  the  anthropological  laboratory,  were  engaged 
during  the  summer :  Dr.  G.  M.  West,  in  Quebec  and  the  maritime 
provinces  of  Canada ;  Mr.  T.  F.  Holgate,  in  eastern  Ontario ;  Dr.  T. 
Proctor  Hall,  in  western  Ontario ;  Mr.  T.  L.  Bolton,  in  Idaho  and  Utah. 
Other  observers  were  similarly  employed  in  Alaska,  British  Columbia, 
the  northwest  territories  of  Canada,  Labrador,  Dakota,  Wisconsin, 
Washington,  Oregon,  New  Mexico,  Yucatan,  etc.  The  chief  object  of 
the  extensive  investigation  thus  begun  is  to  show  the  distribution  of 
types  over  the  American  continent,  and  to  settle,  if  possible,  disputed 
points   regarding   the   physical   anthropology   of   the   Indians.      In   the 


150  Anthropology. 

summer  of  1891  Dr.  Boas  resumed  his  investigations  of  the  Indians  of 
British  Cohxmbia  for  the  British  Association,  and  also  visited  the  last 
survivor  of  the  Chinook  tribe,  from  whom  he  obtained  very  valuable 
ethnologic  and  linguistic  data. 

During  the  academic  years,  1889-92,  Dr.  Walter  Channing,  of  Brook- 
line,  Mass.,  Honorary  Fellow  of  the  University,  carried  on  original  investi- 
gations in  the  laboratory  of  the  department. 

In  November,  1890,  Dr.  G.  M.  West  (afterward  Instructor  in 
Anthropology  in  the  University  of  Chicago),  a  graduate  of  Columbia 
College,  was  appointed  Fellow  (and  afterward  Assistant)  in  Anthro- 
pology, and  devoted  himself  to  the  consideration  of  its  physical  side, 
taking  a  large  part  in  the  anthropometric  investigations  begun  in  the 
Worcester  schools.  During  the  summer  of  1891  Dr.  West  was  engaged 
in  anthropological  measurements  of  the  Indian  tribes  of  Quebec  and  the 
maritime  provinces  of  Canada.  Appointed  Assistant  in  Anthropology  in 
1891,  he  continued  in  that  position  until  the  close  of  the  academic  year 
1891-92,  when  he  became  associated  with  Dr.  Boas  in  the  sub-depart- 
ment of  anthropology  in  the  World's  Columbian  Exposition,  having 
charge  of  the  anthropological  investigations  during  Dr.  Boas's  absence  in 
Europe. 

During  the  Docentship  of  Dr.  Boas  the  lectures  of  the  department 
were  as  follows  :  — 

1.  A  course  of  lectures  on  :  Physical  Anthropology,  Osteology,  and 
particularly  Craniology.  The  Physical  Character  of  the  living  subject  : 
Anatomy  of  Races.  In  connection  with  these  lectures  practical  work  was 
carried  on  in  the  laboratory. 

2.  A  course  of  lectures  on  :  The  Anthropology  of  Africa,  embracing 
the  consideration  of  the  geographical  distribution,  physical  characters, 
languages,  and  culture  of  the  native  tribes. 

3.  A  course  of  lectures  on:  The  Application  of  Statistics  to  Anthro- 
pology. 

In  the  spring  of  1892  Dr.  West  delivered  a  course  of  lectures  on 
The  Growth  of  School  Children,  based  upon  the  results  obtained  in  the 
Worcester  schools.  These  lectures  have  been  published  in  Science  and 
the  Archiv  filr  Anthropologie. 

In  the  spring  of  1890  Mr.  A.  F.  Chamberlain,  a  graduate  of  the 
University  of  Toronto,  then  Fellow  in  Modern  Languages  in  University 
College,  Toronto,  who  had  been  a  student  in  ethnology  under  the  late  Sir 


Anthropology.  151 

Daniel  Wilson,  was  appointed  to  the  first  fellowship  created  in  anthro- 
pology in  the  University.  Previous  to  entering  upon  the  course  of  study 
for  the  doctorate,  Mr.  Chamberlain  had  made  special  investigations  of 
the  Algonkian  Indian  languages,  and  these  he  continued,  offering  as  his 
thesis  an  original  monograph,  "  The  Language  of  the  Mississagas  of 
Skugog,"  which  was  published  in  1892.  Other  briefer  essays  in  the 
same  field  have  appeared  in  the  Proceedings  of  the  Canadian  Institute 
(Toronto),  Canadian  Indian,  American  Anthropologist,  Journal  of  Ameri- 
can Folk-Lore,  Proceedings  of  the  American  Association  for  the  Advancement 
of  Science,  etc.,  during  the  years  1888-99. 

Time  snatched  from  busy  hours  from  1891  to  1893  was  devoted  to 
original  investigations  in  the  language  and  folk-lore  of  the  Canadian 
French,  some  results  of  which  have  been  published  in  Modern  Language 
Notes  (Baltimore),  Vols.  6-8.  In  1892  was  published  the  result  of  an 
extensive  investigation  of  the  use  of  "  Diminutives  in  -ing,''  in  the  Platt- 
Deutsch  (Low  German)  dialects,  another  study  from  which  field,  "Color 
Comparisons  in  the  Low  German  Dialects,"  subsequently  appeared. 

In  the  spring  of  1891  Dr.  Chamberlain  delivered  a  brief  course  of 
lectures  on  "  The  Relationship  of  Linguistics  to  Psychology  and  Anthro- 
pology." In  the  fall  of  the  same  year  he  assisted  in  the  anthropometric 
investigations  carried  on  in  the  schools  of  the  city  of  Worcester  under 
the  direction  of  Dr.  Boas,  and  in  April-May,  1892,  superintended  the 
measurements  of  some  15,000  school  children  in  Toronto,  Canada,  the 
results  of  which  work  are  being  from  time  to  time  published  (see  Report 
of  Commissioner  of  Education,  1896-97,  Vol.  2)  by  Dr.  Boas,  under  whose 
auspices  it  was  carried  out. 

From  June  to  October,  1891,  he  was  absent  among  the  Kootenay 
Indians  of  southeastern  British  Columbia  and  Northern  Idaho,  having 
been  selected  by  the  committee  of  the  British  Association  for  the  Ad- 
vancement of  Science  to  carry  on  anthropological  investigations  among 
the  Indian  tribes  of  northwestern  Canada.  His  report  (discussing  in 
detail  the  ethnography,  physical  anthropology,  mythology,  and  language 
of  this  comparatively  unknown  aboriginal  people)  was  presented  at  the 
Edinburgh  (1892)  meeting  of  the  Association  and  printed,  with  an 
introduction  by  Horatio  Hale,  as  the  "  Eighth  Report  on  the  Northwestern 
Tribes  of  Canada"  (London,  1892,  71  pp.).  Other  briefer  studies, 
botanical,  linguistic,  mythological,  psychological,  based  upon  the  material 
gathered  during  this  expedition,  have  been  published  in  the   American 


152  Anthropology. 

Anthropologist^  American  Antiquarian^  Journal  of  American  Folk-Lore^ 
Verhandlwigen  der  Berliner  anthropologischen  Gesellschaft,  Archivio  per 
V Antropologia,  Am  Ur- Quell,  Science,  etc.  The  great  mass  of  material, 
however,  is  still  in  process  of  preparation  for  publication,  and  will,  when 
complete,  make  some  four  good-sized  treatises  or  volumes  as  follows  :  — 

1.  Kootenay  Indian  Art.     An  Interpretative  and  Comparative  Study  of  some 

Three  Hundred  Drawings  of  Natural  Objects,  Human  Beings,  Animals,  etc., 
made  by  various  Indians  of  the  Upper  and  Lower  Kootenay. 

2.  Mythology  of  the  Kootenay  Indians.    A  Comparative  and  Interpretative  Study 

of  some  Fifty  Animal  Tales  and  Legends  of  the  Kootenay  Indians.     With 
original  Indian  Text,  Translation,  Explanatory-  Notes,  etc. 
3-4.   Dictionary  of  the  Kootenay  Language,  with  Introduction  on  Grammar  and 
Morphology.     Part  I.,  Kootenay-English ;  Part  II.,  English-Kootenay. 

As  much  time  as  could  reasonably  be  spared  from  other  duties  has 
been  devoted  to  the  long  and  difficult  task  of  compilation  and  revision  of 
these  original  studies. 

During  his  tenure  of  the  Lectureship  in  Anthropology,  Dr.  Chamber- 
lain has  lectured  twice  a  week  throughout  the  academic  year,  the  following 
courses  having  been  delivered :  — 

1892-93.   Mythology  of  the  North  American  Indians. 

The  syllabus  and  bibliography  of  this  detailed  interpretative  study  have 
been  published  in  the  "  Third  Annual  Eeport  of  the  President  to  the  Trustees 
of  Clark  University,"  1893,  pp.  123-125,  141-161.  Several  of  the  lectures  have 
appeared  in  full,  or  in  abstract,  in  the  Journal  of  American  Folk-Lore. 

1893-94.  General  Course :  The  Science  of  Anthropology  in  its  Eelations  to 
Psychology  and  Pedagogy.  Special  Courses :  (a)  Comparative  Mythology 
of  Ancient  Greece  and  Italy ;  (6)  Child  Life  among  Primitive  Races,  the 
American  Indians  especially. 

The  introductory  lecture  of  this  course,  under  the  title  ''Anthropology  in 
Universities  and  Colleges,"  with  brief  historical  bibliography,  has  been  pub- 
lished in  part  in  the  Pedagogical  Seminary,  Vol.  3,  pp.  48-60.  An  abstract  of 
one  of  the  lectures  in  course  (b)  has  appeared  as  "Notes  on  Indian  Child 
Language,"  in  the  American  Anthropologist,  Vol.  3,  pp.  237-241 ;  Vol.  6,  pp. 
321-322. 

1894-95.  Besides  the  course  in  General  Anthropology,  the  following  brief 
special  courses  were  delivered :  Anthropology  and  Ethnology  of  Sex  ;  The 
Child  amongst  Primitive  Peoples  ;  Comparative  Mythology  of  America  and 


Anthropology.  153 

the  Old  World;  Psychology  of  Primitive  Languages;  The  Beginnings  of 
Art  and  Language ;  The  iEsthetical  Ideas  of  Primitive  Peoples. 

The  lectures  on  the  "  Psychology  of  Primitive  Languages "  were  based  upon 
original  investigations  among  the  Algonkian  Indians  of  Canada,  and  the  Koote- 
nay  Indians  of  British  Columbia,  and  abstracts  of  several  of  them;  have  been 
published  in  the  American  Anthropologist,  Vol.  7  (1894),  pp.  68-69,  186-192 ; 
VerJiandlungen  der  Berliner  antliropologischen  Gesellschaft,  1893,  pp.  421-425, 
1895,  pp.  551-556 ;  Arcliivio  per  V  Antropologia  e  la  Etnologia  (Firenze),  Vol. 
23  (1893),  pp.  393-399. 

The  lectures  on  "The  Child  among  Primitive  Peoples,"  delivered  also  in 
popular  form  at  the  Summer  School  in  July,  1894,  have  been  elaborated  and 
published  as  a  book,  with  the  title  "  The  Child  and  Childhood  in  Folk-Thought " 
(New  York,  Macmillan,  1896). 

1895-96.  Besides  the  course  in  General  Anthropology,  the  following  special 
and  briefer  courses  were  delivered:  Anthropometry  of  Children  and  Youth; 
The  Emotions  and  their  Expression  among  Primitive  Paces ;  The  Idea  of 
the  Soul  among  Primitive  Peoples ;  Crime  and  Degeneracy  among  the  Lower 
Paces  of  Man ;  Origin  and  Development  of  the  Family ;  Sociological  History 
of  Woman. 

Two  of  the  lectures  on  "  The  Emotions  and  their  Expression  among  Primi- 
tive Peoples  "  have  appeared  in  part  in  the  American  Journal  of  Psychology, 
Vol.  10,  pp.  301-305,  "Fear,"  and  Vol.  6,  pp.  585-592,  "Anger." 

1896-97.  Besides  the  course  in  General  Anthropology,  the  following  briefer 
special  courses  were  delivered :  The  Philosophy  of  Primitive  Mythologies ; 
Origin  and  Development  of  Social  Institutions;  Race-Psychology;  The 
Anthropology  of  Childhood ;  Civilization  and  Evolution. 

One  of  the  lectures  in  the  course  on  "The  Philosophy  of  Primitive  My- 
thology" appears,  under  the  title  "Folk-Lore  and  Mythology  of  Invention,"  in 
the  Journal  of  American  Folk-Lore,  Vol.  10  (1897),  pp.  89-100. 

1897-98.  Besides  the  course  in  General  Anthropology,  the  following  briefer 
special  courses  were  delivered :  The  Anthropology  of  Sex ;  Primitive  Children 
and  Children  of  Civilized  Races ;  Social  Evolution ;  Origin  and  Development 
of  Primitive  Religions ;  Anthropometry. 

1898-99.  Besides  the  course  in  General  Anthropology,  the  following  special 
briefer  courses  have  been  delivered :  Child  Study  in  Italy,  Variation  and 
Degeneration,  Heredity  and  Environment. 

Outside  of  the  academic  and  summer  school  courses  the  following 
lectures  and  addresses  on  topics  of  general  interest  have  been  delivered 
from  time  to  time  in  Worcester  and  elsewhere  :  — 


154  An  th  1  'opology. 

1892.     Aims   and  Methods   of  Anthropometry.     Principals  and  Teachers  of 
Grammar  Schools,  Toronto. 

1892.  Optimism.     Canadian  Club,  Clark  University,  Worcester. 

1893.  Savage  Views  of  Nature.     Natural  History  Society,  Worcester. 

1893.  The  American  Indian.     Men's  Association,  Pilgrim  Church,  Worcester, 

Mass. 

1894.  Woman's  Role  in  the  Development  of  Eeligion  and  Civilization.     Fort- 

nightly Club,  Woonsocket,  R.I. 

1895.  The  World's  Debt  to  the  Red  Man.     Natural  History  Society,  Sterling, 

Mass. 

1895.  The  Mother  and  the  Child  in  the  Story  of  Religion  and  Civilization. 

South  Unitarian  Church,  Worcester,  Mass. 

1896.  Childhood.     Conference  of  Lend-a-Hand  Clubs,  Lowell,  Mass. 
1896.     The  American  Indian.     Universalist  Church,  New  Britain,  Conn. 

1896.  The  Making  of  Abraham  Lincoln.     South  Unitarian  Church,  Worcester, 

Mass. 

1897.  Johanna   Ambrosius.      Lend-a-Hand   Clubs,    South   Unitarian   Church, 

Worcester,  Mass. 
1897.     Youth.     Lend-a-Hand  Conference,  Boston,  Mass. 
1897.     Lincoln  and  Darwin.     South  Unitarian  Church,  Worcester,  Mass. 
1897.     In  Memoriam :  Henry  George.  South  Unitarian  Church,  Worcester,  Mass. 

1897.  The    Unitarian    Church    and    Alcoholism.      Conference   of    Unitarian 

Churches,  Barre,  Mass. 

1898.  Primitive  Nature  Study.     Jacob  Tome  Institute,  Port  Deposit,  Md. 

1899.  The  Child  and  the  Criminal.    Monday  Morning  Club  (Universalist  Min- 

isters), Boston,  Mass. 

At  the  meetings  of  various  scientific  societies,  1890-99,  the  following 
papers  have  been  presented,  those  marked  *  having  been  published  since 
their  delivery :  — 

1.  American  Folk-Lore  Society :  — 

1890.  *Nanibozhu  among  the  Otcipwe,  etc. 

1892.   *Physiognomy  and  Physical  Characteristics  in  Folk-Lore  and  Polk- 
Speech. 

1892.  Christ  in  Folk-Lore. 

1893.  Mythology  of  the  Columbian  Discovery  of  America. 

1895.  *Poetical  Aspects  of  American  Aboriginal  Speech. 

1896.  *Folk-Lore  and  Mythology  of  Invention. 

1898.   *American  Indian  Names  of  "White  Men  and  Women. 

2.  Modern  Language  Association  of  America :  — 

1891.  *The  Use  of  Diminutives  in  -inrj  by  some  writers  in  Low  German 

Dialects. 


Anthropology.  155 

3.  American  Association  for  the  Advancement  of  Science :  — 

1893.  Primitive  Woman  as  Poet. 

1894.  *Translation  into  Primitive  Languages.     (Abstract.) 
1894.    *Incorporation  in  the  Kootenay  Language. 

1894.  ^'Primitive  Anthropometry  and  its  Folk-Lore.     (Abstract.) 

1895.  *Kootenay  Indian  Personal  Names. 

=*Word  Formation  in  the  Kootenay  Language. 

4.  British  Association  for  tlie  Advancement  of  Science :  — 

1892.  *Kootenay  Indians. 

1897.    *Kootenay  Indian  Drawings.     (Abstract.) 

1897.   *The  Kootenays  and  their  Salishan  Neighbors.     (Abstract.) 

5.  Berliner  Anthropologische  Gesellschaf t :  — 

1893.  *Wurzeln  aus  der  Sprache  der  Kitonaqa-Indianer. 
1895.   *Beitrag  zur  Pflanzenkunde  der  Naturvolker  America's. 

6.  International  Congress  of  Anthropology  (Chicago)  :  — 

1893.   *The  Coyote  and  the  Owl.     (Tales  of  the  Kootenay  Indians.) 

Dr.  Chamberlain  has  been  a  Councillor  of  the  American  Folk-Lore 
Society  (1894),  Secretary  of  the  Anthropological  Section  of  the  Ameri- 
can Association  for  the  Advancement  of  Science  (1894),  and  one  of  the 
secretaries  of  the  Anthropological  Section  of  the  British  Association  for 
the  Advancement  of  Science  (1897). 

Since  1894  anthropology  has  been  represented  on  the  programme  of 
the  Summer  School  of  the  University,  and  each  year  Dr.  Chamberlain  has 
delivered  a  course  of  twelve  daily  lectures  upon  anthropological  questions 
and  topics  of  more  or  less  interest  to  the  teacher  and  to  the  general  public. 
These  courses  have  been  as  follows  :  — 

1894.  Anthropology  of  Childhood.     (The  Child  Among  Primitive  Peoples.) 

1895.  Pedagogical  and  Psychological  Aspects  of  Anthropology. 

1896.  Anthropology  of  Childhood.     (New  Series.) 

1897.  Anthropological  Aspects  of  Childhood. 

1898.  The  Beginnings  of  Education  and  Educational  Institutions.  —  Primitive 

Pedagogy. 

1899.  Educational  Aspects  of  Human  Evolution. 

At  the  various  summer  schools  the  following  topics  have  also  been 
popularly  treated  in  evening  lectures  :  — 

1896.    (a)  The  Philosophy  of  Childhood  with  the  Poets. 
(6)  The  Genius  of  Childhood. 


156  Anthropology. 

1897.  (a)  The  Divinity  of  Childhood. 

(6)  The  Attitude  of  Primitive  Peoples  toward  Nature. 

1898.  The  Childhood  of  Genius. 

1899.  (a)  The  Prophecy  of  Childhood. 

(&)  The  Making  of  a  Genius.     (Abraham  Lincoln.) 

Anthropology,  while  comparatively  a  new,  is  by  no  means  an  uncom- 
mon, subject  of  academic  instruction,  and  the  time  has  distinctly  passed 
when  it  should  be  called  upon  to  plead  for  its  existence,  or  to  make  an 
oratio  pro  domo. 

Very  many  of  the  great  European  universities  have  specifically  rec- 
ognized anthropology  as  worthy  of  the  highest  positions  in  their  gift, 
and,  in  this  country,  institutions  like  Harvard,  Columbia,  Chicago,  and 
the  University  of  Pennsylvania  have  endued  this  department  with  the 
full  dignity  of  a  professorship.  Moreover,  nearly  twenty  other  colleges 
and  universities  in  America  now  offer  instruction  in  anthropology,  as 
such,  while  Sociology,  one  of  the  most  important  branches  of  the  science, 
is  to  be  found  on  the  curriculum  of  all  such  institutions  as  are  making 
any  efforts  whatsoever  to  keep  abreast  of  the  times.  Other  branches  of 
anthropology,  such  as  Comparative  Philology,  Comparative  Religion, 
Race  Psychology,  Anthropometry,  Archaeology,  Culture-History,  etc.,  are 
finding  more  and  more  acceptance  with  the  higher  institutions  of  learning. 

Both  with  respect  to  original  research  and  to  academic  lectures,  the 
representatives  of  anthropology  in  American  universities  have  no  reason 
to  fear  comparison  with  the  professors  and  instructors  in  any  other  branch 
of  science,  and  their  influence  in  broadening  and  humanizing  some  of 
the  more  belated  and  conservative  of  the  kindred  branches  of  human 
knowledge  can  hardly  be  overestimated. 

It  is  a  significant  fact  that  the  latest  and  most  complete  academic 
recognition  of  anthropology,  the  promotion  of  Dr.  Franz  Boas  to  a  profes- 
sorship in  Columbia  University,  does  just  honor  to  one  who  began  his 
academic  career  as  a  Decent  in  Clark  University  in  1890.  How  much  of 
the  interest  in  anthropology  in  other  institutions  of  learning  can  be  legiti- 
mately traced  to  this  University,  which,  in  1892,  conferred  the  first  Ph.D. 
ever  granted  in  America  for  research  and  investigation  in  anthropological 
science,  cannot  readily  be  ascertained,  but  its  influence,  both  direct  and 
indirect,  has  been,  no  doubt,  as  it  still  is,  very  great.  Proofs  of  this  are 
not  wanting  in  the  curricula  of  more  than  one  of  the  higher  institutions 
of  learning,  while  the  course  in  anthropology  in  the  University  of  Illinois, 


Anthropology.  157 

offered  by  Dr.  Arthur  H.  Daniels,  a  graduate  of  Clark  University,  is 
directly  due  to  the  initiative  and  encouragement  of  the  department  of 
anthropology. 

Through  the  lectures  delivered  at  the  University  and  during  the 
Summer  School,  the  anthropological  department  has  exercised  an  ever 
increasing  influence,  which  has  been  added  to  by  the  appearance  of  one 
series  of  these  lectures  in  book  form.  Another  point  of  contact  with  the 
teaching  profession  throughout  the  country  lies  in  the  use  of  the  depart- 
ment as  a  sort  of  bureau  of  information  upon  many  and  varied  topics  of 
educational  science.  During  the  last  year,  especially,  very  many  requests 
for  such  information  have  been  received  and  responded  to,  often  in  detail 
and  as  the  result  of  personal  research.  To  the  students  of  the  University 
the  department  of  anthropology  has  always  emphasized  the  great  value 
of  a  bibliographical  knowledge  of  the  subject  under  investigation,  and 
its  services  have  always  been  at  their  disposal. 

In  this  University  anthropology  ranks  as  a  branch  of  psychology,  and 
to  promote  and  advance  it  as  such  has  been  the  constant  aim  and  endeavor 
of  its  representative  on  the  Faculty.  The  lectures  have  been  such  as  to 
correlate  with  the  instruction  given  in  philosophy,  psychology,  and  peda- 
gogy, and  their  object  has  been  to  furnish  the  students  in  those  depart- 
ments with  the  most  recent  results  of  anthropological  investigations,  and 
to  imbue  them  with  that  wider  and  deeper  thought  that  comes  from  the 
contemplation  of  the  history  of  individual  and  of  racial  man,  and  to  lay 
firm  foundations  upon  which  in  years  to  come  may  rise  a  complete  and  per- 
fectly equipped  department  of  anthropology.  A  glance  at  the  theses  and 
essays  in  the  departments  of  philosophy  and  psychology  will  demonstrate 
the  way  in  which  the  department  has  advantaged  those  who  have  pro- 
ceeded to  their  degrees  in  this  University,  such  subjects  as  "Regeneration," 
"Dolls,"  "Migration,"  "  Hydi'o-Psychoses,"  "  Dendro-Psychoses,"  "Im- 
mortality," "  Teaching  Instinct,"  "  Philosophy  of  Education,"  "Adoles- 
cence," "Degeneracy,"  etc.,  naturally  calling  upon  anthropology  for  its 
quota  of  fact  and  information,  which  has  often  been  quite  large  and  sig- 
nificant. Especially  has  this  been  the  case  since  "Child-study"  has  loomed 
up  so  largely  in  the  field  of  education,  for  questions  of  heredity  and  environ- 
ment, recapitulation,  atavism  and  reversion,  degeneration,  variation,  genius, 
and  the  like,  must  receive  from  anthropology,  more  or  less,  their  true 
orientation  and  interpretation,  —  the  science  of  the  child  would  be  help- 
less  without   the   science  of   man,  the  story  of  the  individual  not  half 


158  Anthropologij. 

understood  without  the  story  of  the  race.  The  greater  prominence  now 
being  given  to  individual  psychology,  brings  psychology  also  into  closer 
and  better  touch  with  anthropology.  That  the  first  woman  to  hold  a 
fellowship  in  any  department  in  Harvard  University  was  an  anthropolo- 
gist is  a  fact,  which,  taken  in  connection  with  the  great  amount  of  excel- 
lent original  work  done  in  anthropology  by  women,  both  in  Europe  and 
in  America,  augurs  well  for  the  future  advancement  of  the  science,  when 
all  institutions  offering  post-graduate  instruction  in  anthropology  and 
facilities  for  original  investigation  shall  have  been  opened  to  women  upon 
the  same  terms  as  to  men.  The  composite  character  of  the  population  of 
the  United  States,  the  existence  within  its  borders  of  several  entirely  dis- 
tinct races,  and  the  addition  to  these  resulting  from  the  recent  acquisition 
of  outlying  and  distant  possessions,  must  inevitably  tend  to  make  anthro- 
pology more  and  more  a  real  academic  necessity,  no  less  than  a  constant 
factor  in  the  determination  of  national  welfare  and  progress.  Unless 
every  sign  fails,  the  history  of  anthropology  in  the  next  quarter  century 
of  American  university  life  will  compare  in  brilliancy  with  that  of  any 
other  science  similiarly  stimulated  and  environed. 

At  this  University,  anthropology  has  accomplished,  as  the  record  of 
the  publications  of  the  department  shows,  results  out  of  proportion  to  its 
financial  resources  and  the  facilities  for  investigation  and  research  made 
possible  thereby.  With  other  departments  in  the  University  it  has  striven 
to  overcome  these  serious  handicaps  as  much  as  might  be,  and  what  has 
already  been  done  must  serve  to  indicate  what  can  be  done  in  the  future, 
if  the  department  is  generously  and  satisfactorily  endowed.  Nowhere 
else,  perhaps,  can  the  "  sinews  of  science,"  rightly  employed,  give  ampler 
or  juster  returns,  if  the  past  foreshadows  the  years  to  come. 

Clark  University,  the  first  institution  in  America  to  recognize  anthro- 
pology as  a  fit  and  proper  subject  for  post-graduate  researches  and  inves- 
gation  leading  to  the  degree  of  Ph.D.,  and  the  first  university  to  confer 
such  a  degree,  can  justly  hope  for  that  recognition  which  comes  to  the 
pioneers  in  all  great  educational  movements. 

But  before  the  department  can  labor  at  its  best,  it  must  have  the  best 
means  of  research  and  investigation,  be  equipped  as  well,  at  least,  as  any 
similar  department  in  any  other  institution  in  the  country.  Given  these, 
it  can  do  as  good  work,  or  even  better. 

The  professorships  at  Harvard,  Columbia,  Chicago,  and  Pennsylvania, 
the  Thaw  Fellowship  at  Harvard,  the  library  of  20,000  books  and  pam- 


Antliroijology,  159 

phlets  in  a  single  branch  of  anthropology  at  the  University  of  Pennsyl- 
vania, and  the  laboratory  and  museum  facilities  of  all  these  institutions 
which  have  come  into  such  rich  fruition  during  the  last  ten  years,  point 
the  way  for  us,  if  the  good  work  of  the  past  is  to  increase  and  multiply. 
For  comparison  with  the  present  state  of  affairs  at  this  University,  the 
following  data  from  the  most  recent  official  publications  of  the  universi- 
ties concerned,  institutions  which  offer  post-graduate  courses  in  anthro- 
pology and  confer  the  degree  of  Ph.D.  in  that  department,  will  suffice 
(sociology,  etc.,  not  included):  — 

Harvard:  Professor;  Instructor;  Thaw  Fellow   ($1050);   Hemenway  Fellow 

($500)  ;  Winthrop  Scholar  ($200). 
Chicago :   Associate  Professor ;  one  Fellow. 
Columbia :  Professor ;  two  Instructors ;  President's  University  Scholar  ($150) ; 

one  Fellow ;  two  Scholars. 

One  cannot  escape  seeing  the  necessity  of  enlargement  and  further 
endowment  at  this  University,  if  anthropology  is  to  prosper  fully. 

Before  the  great  things  of  which  it  is  capable  can,  in  all  their  rounded 
completeness,  be  accomplished  here,  changes  and  improvements  must 
take  place,  and  the  following  are  among  those  most  needed  or  most 
desirable :  — 

(1)  The  department  must  ultimately  be  dignified  by  the  existence 
of  a  professorship,  if  it  is  to  continue  to  hold  its  own  among  the  similar 
departments  in  other  great  educational  institutions.  Anthropology  can 
wait,  as  it  has  waited,  but  it  scarcely  deserves  that  refusal  of  academical 
advancement,  which  is,  of  necessity,  bound  up  with  straitened  financial 
conditions. 

(2)  A  complete  departmental  library,  which  shall  include  all  cur- 
rent periodicals  and  journals  of  anthropological  interest  and  afford  imme- 
diate access  to  the  very  latest  American  and  foreign  publications  in  all 
branches  of  anthropological  science,  is  an  absolute  necessity.  The  ad- 
vantage of  having  all  these  under  one  roof  and  procurable  immediately 
after  their  issuance  is  inestimable. 

(3)  A  thoroughly  equipped  laboratory,  for  special  researches  and 
investigations,  is  also  among  the  things  first  to  be  desired,  and  what 
investigators  now,  or  formerly  connected  with  the  University,  have  done 
in  this  field  is  a  full  guarantee  that  such  an  addition  to  the  facilities  of 
the  University  would  be  well  utilized  and  appreciated. 


160  Anthropology. 

(4)  A  museum,  which  shall  contain  materials  and  specimens  illustrating 
the  parallel  development  of  the  individual  and  the  race,  is  also  a  desidera- 
tum, for  this  truly  anthropological  theory,  so  fecund  for  education  and 
psychology,  has  yet  to  undergo  that  stern  test  which  zoology,  palaeon- 
tology, and  geology  have  so  successfully  sustained. 

(5)  Generous  endowment  of  fellowships  and  scholarships  (intra-mural 
and  extra-mural)  and  other  aids  in  investigation  and  field  work  is  abso- 
lutely necessitated  by  any  adequate  instalment  of  anthropology. 

(6)  More,  perhaps,  than  is  the  case  with  most  other  departments,  lib- 
eral allowances  for  clerical  work  and  for  travelling  expenses,  the  lack  of 
which  so  often  delays  good  studies  and  inconveniences  good  men,  are  nec- 
essary, and  the  department  must  be  congratulated  on  what  has  been 
achieved  in  the  absence  of  all  these.     Often  to  be  able  means  to  accomplish. 

Judged  both  by  the  work  accomplished  here  and  the  status  of  anthro- 
pology in  other  universities,  the  department  has  every  reason  to  ask 
and  every  right  to  expect  such  increased  endowment  as  will  enable  it  to 
make  the  next  ten  years  of  its  existence  as  notable  as  the  same  period  in 
the  history  of  anthropology  in  any  of  the  higher  institutions  of  learning, 
European  or  American. 


PEDAGOGY. 

By  William  Henry  Burnham. 

Soon  after  the  opening  of  the  University,  President  G.  Stanley  Hall 
entered  upon  the  duties  of  Professor  of  Psychology  and  Education. 
During  the  first  academic  year  no  pedagogical  courses  were  given,  but 
toward  the  close  of  the  year  Dr.  William  H.  Burnham,  the  writer  of  this 
report,  was  appointed  Docent  in  Pedagogy  and  sent  to  Europe  by  the 
University  to  study  educational  institutions,  methods,  etc.  During  the 
year  1890-91,  courses  of  lectures  on  pedagogy  were  given  in  the  psycho- 
logical department  by  Drs.  Hall  and  Burnham,  and  a  seminary  met  weekly 
for  the  study  and  discussion  of  educational  subjects.  In  1893  the  educa- 
tional courses  were  designated  as  a  sub-department  of  psychology  offering 
a  minor  for  the  doctor's  degree.  But  the  work  has  remained  most  inti- 
mately connected  with  that  in  psychology  and  anthropology. 

In  any  natural  development  of  these  three  subjects,  the  subject-matter 
overlaps  and  is  interrelated.  In  this  University  no  attempt  has  been 
made  to  mark  a  line  of  division  between  them.  Specially  close  has  been 
the  connection  between  psychology  and  pedagogy,  most  of  the  students 
in  one  subject  taking  courses  in  the  other.  Such  vital  connection  of  the 
two  subjects  has  mutual  advantages.  Pedagogy  is  based  upon  psychology 
and  owes  to  it  the  inspiration  and  stimulus  to  scientific  work,  and  psy- 
chology owes  to  pedagogy  the  suggestion  of  some  of  its  most  fruitful 
fields  of  investigation. 

With  a  limited  staff  no  attempt  has  been  made  to  cover  the  whole 
field  of  pedagogy  ;  but  by  choosing  specially  important  parts  of  the  field, 
and  by  extending  the  courses  over  two  or  three  years,  an  effort  has  been 
made  to  show  how  the  subject  should  be  studied.  By  this  method  lectures 
have  been  given  on  the  history  of  the  modern  reform  movement  in  educa- 
tion, begun  on  the  one  hand  by  the   early   Italian   Humanists,  and  on 

M  161 


162  Pedagogy. 

the  other  by  Comenius,  the  present  organization  of  schools  in  England, 
France,  and  Germany,  the  Evolution  of  the  Teaching  Profession,  the 
Historical  and  Critical  Study  of  Educational  Principles,  Mental  and 
Physical  Development,  Educational  Psychology,  and  School  Hygiene, 
including  the  Hj'giene  of  Instruction.  Other  courses  have  been  given 
by  Drs.  Hall,  Burnham,  and  Lukens  on  the  following  among  other 
topics  :  History  of  Methods  in  Reading,  Physical  Education,  Child-study, 
Adolescence,  Ideal  School,  Herbartian  Pedagogy,  History  of  Curricula, 
and  leading  present  toj^ics  in  education. 

A  great  variety  of  subjects  have  been  studied  in  connection  with  the 
seminaries,  and  the  results  of  many  of  these  studies  have  appeared  in  the 
Pedagogical  Seminary,  an  educational  journal  edited  by  G.  Stanley  Hall 
and  published  at  the  University,  beginning  in  1891.  The  work  of  the 
department  is  best  seen,  however,  by  noting  its  aims,  methods,  and 
concrete  results. 

The  aim  of  the  department  is  twofold :  first,  to  give  instruction  and 
training  to  those  who  are  preparing  to  be  professors  of  pedagogy,  super- 
intendents, or  -teachers  in  higher  institutions ;  second,  to  make  scientific 
contributions  to  education.  These  two  ends  are  so  closely  related  that 
the  pursuit  of  one  involves  much  of  the  work  required  for  the  other  also. 
Suitable  preparation  for  the  course  involves  so  much  of  general  edu- 
cation as  is  usually  indicated  by  the  B.A.  degree.  A  good  reading 
knowledge  of  French  and  German  is  of  vital  importance,  and  an  acquaint- 
ance with  elementary  psychology  is  desirable,  it  being  taken  for  granted, 
of  course,  that  those  who  intend  to  teach  have  adequate  knowledge  in 
their  own  special  departments. 

Assuming  that  a  student  has  adequate  preparation,  three  things  are 
essential  for  higher  pedagogical  training :  first,  a  general  knowledge  of 
the  organization  of  education  in  different  countries  and  of  literature  in  the 
field  of  education,  including  the  history  of  education,  psychology  in  its 
relation  to  education,  and  school  hygiene;  second,  actual  experience  in 
teaching,  together  with  observation  of  good  teaching,  and  some  direct 
study  of  educational  institutions  of  different  character  and  grade ;  third, 
some  experience  in  independent  research,  involving  not  only  the  thorough 
study  of  all  authorities  upon  a  subject,  and  of  all  work  that  has  been  done 
in  the  same  field  in  different  countries,  but  also  original  investigation 
leading  to  a  scientific  contribution. 

These  three  kinds  of  work  may  be  done  simultaneously  or  successively. 


Pedagogy.  163 

In  some  of  the  best  higher  pedagogical  seminaries  in  Germany  they  are 
done  simultaneously.  Students  study  and  report  upon  educational  and 
psychological  literature.  They  visit  classes  of  different  grades,  observing 
the  work  of  regular  teachers,  and  also  teach  in  a  practice  school.  At  the 
same  time  they  endeavor  to  investigate  some  special  problem.  In  this 
University  the  study  of  educational  literature,  by  lectures  and  inde- 
pendent reading,  and  the  investigation  of  some  problem,  are  usually  car- 
ried on  simultaneously ;  but  practical  experience  in  teaching  must  be 
gained  before  or  after  the  University  course.  There  are  some  advan- 
tages in  doing  actual  teaching  simultaneously  with  the  study  and  investi- 
gation of  educational  problems.  Direct  experience  in  the  school  makes 
investigation  more  vital  and  practical,  and  is  an  important  control  in 
scientific  research.  But,  while  at  present  the  University  has  no  practice 
school,  as  a  matter  of  fact,  most  of  those  who  have  been  members  of  the 
educational  department  have  had  experience  in  teaching  before  coming 
to  the  University ;  and  the  lack  of  direct  connection  with  the  schools  is 
in  part  supplied  by  visits  to  educational  institutions.  Moreover,  there 
is  no  rigid  line  between  instructors  and  students  in  the  department.  Both 
are  teachers  and  learners  in  turn.  Special  emphasis  is  placed  upon  the 
importance  of  research ;  and  much  of  the  time  of  the  instructors  is  spent 
in  consultation  with  individual  students  in  regard  to  their  investigations. 
President  Hall  especially  has  given  a  large  amount  of  attention  to  direct- 
ing this  work.  The  research  undertaken  has  been  largely  in  the  field 
of  genetic  psychology  and  related  subjects  ;  and  the  students  have 
been  assisted  by  the  instructors  in  psychology,  anthropology,  and  neu- 
rology. A  great  variety  of  topics,  however,  have  been  studied ;  and 
a  large  part  of  the  investigations  have  yielded  results  for  publication. 
The  papers  ^  that  have  already  appeared  may  be  roughly  classified  as 
follows :  — 

Contributions  to  the  Physiology  and  Psychology  of  Development. 

BOHANNON,  E.  W. :    A  Study  of  Peculiar  and  Exceptional  Children. 
Pedagogical  Seminary^  Oct.,  1896,  Vol.  4,  pp.  3-60. 

Based  upon  answers  to  a  questionnaire  reporting  over  a  thousand 

cases. 

1  Many  of  the  papers  mentioned  in  this  list  are  quite  as  much  products  of  the  department 
of  psychology  as  of  that  of  pedagogy ;  and,  on  the  other  hand,  tlie  pedagogical  department 
has  contributed  to  many  of  the  psychological  studies  mentioned  above. 


164  Pedagogy. 

BOHANNON,  E.  W.:  The  Only  Child  in  a  Family.  Pedagogical 
Seminary,  April,  1898,  Vol.  5,  pp.  475-496. 

From  a  study  of  reports  of  381  only  children,  it  appears  that  only  chil- 
dren are  below  the  average  in  vitality  and  unusually  subject  to  mental 
and  physical  defects  of  a  grave  character,  and  that,  lacking  the  impor- 
tant education  from  the  constant  companionship  of  other  children,  they 
need  special  pedagogical  care  and  training. 

BUKK,  Frederick:  Growth  of  Children  in  Height  and  Weight. 
Am.  Jour,  of  Psg.,  April,  1898,  Vol.  9,  pp.  253-326. 

A  comprehensive  resume  of  the  numerous  studies  in  this  field,  with  a 
discussion  of  their  pedagogical  significance. 

BURK,  Frederick  :  From  Fundamental  to  Accessory  in  the  Devel- 
opment of  the  Nervous  System  and  of  Movements.  Pedagogical 
Seminary,  Oct.,  1898,  Vol.  6,  pp.  5-64. 

A  contribution  to  the  physiology  of  development,  especially  a  study 
of  the  evolution  of  hand  movements  in  the  development  of  the  normal 
child.  From  a  comprehensive  review  of  the  various  neurological  and 
psychological  studies  upon  this  subject,  the  author  makes  among  others 
the  following  conclusion :  that  there  is  an  early  period  in  the  develop- 
ment of  each  part  or  process  when  the  purpose  of  education  must  be  to 
follow  the  fixed  innate  heredity  line  of  tendency  (fundamental  educa- 
tion); that  there  follows  a  later  period  in  an  activity's  development 
when  it  passes  partially  out  of  the  control  of  racial  habit  and  becomes 
more  plastic  to  present  environment  (accessory  education).  Presented 
as  a  dissertation. 

BuKNHAM,  Wm.  H.  :  The  Study  of  Adolescence.  Ihid.,  June,  1891, 
Vol.  1,  pp.  174-195. 

A  brief  introduction  to  the  study  of  the  adolescent  problem. 

BuRNHAM,  Wm.  H.  :  Individual  Differences  in  the  Imaginations  of 
Children.     Ibid.,  March,  1893,  Vol.  2,  pp.  204-225. 

Based  upon  literature  and  reports  by  students  at  the  Worcester 
Normal  School. 

Chrisman,  Oscar  :  The  Secret  Language  of  Children.  Science, 
Dec.  1,  1893,  Vol.  22,  p.  303. 


Pedagogy.  165 

Croswell,  T.  R.  :  Amusements  of  Worcester  School  Children. 
Pedagogical  Seminary^  Sept.,  1899,  Vol.  6,  pp.  267-371. 

A  study  of  the  amusements  of  two  thousand  children  based  upon 
reports  by  the  children.  A  contribution  to  the  problem  of  variation  in 
play  as  conditioned  by  age,  sex,  nationality,  locality,  and  season.  The 
results  indicate  as  characteristic  of  the  games  of  adolescence  the  coopera- 
tion of  a  number  of  individuals  to  secure  a  definite  end,  and  the  delight 
in  contest  in  contrast  with  the  individualistic  amusements  of  earlier 
years. 

Hall,  G.  Stanley:  Initiations  into  Adolescence.  Proc.  Am. 
Antiq.  Soc,  Worcester,  Mass.,  Oct.  21,  1898,  Vol.  12,  pp.  367-400. 

Includes  a  detailed  account  of  certain  rites  of  primitive  peoples,  and 
discusses  the  relation  of  adolescent  instincts  in  religion. 

Lancaster,  E.  G.  :  The  Psychology  and  Pedagogy  of  Adolescence. 
Pedagogical  Seminary,  July,  1897,  Vol.  5,  pp.  61-128. 

A  comprehensive  study  by  the  questionnaire  method.  With  a  resume 
of  the  work  of  others  and  practical  suggestions.  Presented  as  a  disser- 
tation. 

YoDER,  A.  H. :  The  Study  of  the  Boyhood  of  Great  Men.  Ihid.^ 
Oct.,  1894,  Vol.  3,  pp.  134-156. 

Based  upon  the  study  of  a  large  number  of  biographies. 

Studies  of  Special  Branches  of  Education  from  the  Genetic  Point  of  View. 

Ellis,  A.  Caswell  :  Sunday-school  work  and  Bible  Study  in  the 
Light  of  Modern  Pedagogy.  Ihid.^  June,  1896,  Vol.  3,  pp.  363- 
412. 

An  attempt  to  suggest  the  psychological  method  of  religious  instruc- 
tion, together  with  an  historical  sketch  of  the  Sunday-school  idea. 

Johnson,  G.  E.  :  Education  by  Plays  and  Games.  Ihid.^  Oct.,  1894, 
Vol.  3,  pp.  97-133. 

Presents  a  classified  list  of  about  five  hundred  plays  and  games  with 
a  study  of  their  educational  value. 

HoYT,  Wm.  a.  :    The  Love  of  Nature  as  the  Root  of  teaching  and 
learning  the  Sciences.     Ihid.,  Oct.,  1894,  Vol.  3,  pp.  61-86. 
Based  chiefly  upon  literature,  with  pedagogical  suggestions. 


166  Pedagogy. 

LuKENS,  Herman  T.  :    Preliminary  Report  on  the  Learning  of  Lan- 
guage.    Ihid.,  June,  1896,  Vol.  3,  pp.  424-460. 

Traces  the  stages  in  a  child's  learning  to  talk,  and  presents  much  data 
in  regard  to  pronunciation  and  the  development  of  the  sentence. 

LuKENS,   Herman   T.  :    A   Study  of  Children's   Drawings.     Ihid., 
Oct.,  1896,  Vol.  4,  pp.  79-110. 

A  genetic  study  based  upon  original  reports  and  observations. 

Phillips,  D.  E.  :    Number  and  its  Application  psychologically  con- 
sidered.    lUd.,  Oct.,  1897,  Vol.  5,  pp.  221-281. 

Includes  a  study  of  over  two  thousand  arithmetic  papers  prepared 
by  children  in  the  schools,  the  results  of  a  questionnaire  research,  a  criti- 
cal estimate  of  many  text-books,  and  a  discussion  of  the  general  sub- 
ject from  the  genetic  standpoint. 

Street,  J.   R.  :    A  Study  in  Moral  Education.     Ihid.^   July,   1897, 
Vol.  5,  pp.  5-40. 

Based  upon  the  reminiscent  answers  of  adolescents  to  a  questionnaire. 
The  results  suggest  the  great  role  of  imitation,  instruction,  the  sentiments, 
and  heredity  in  moral  action,  and  emphasize  the  significance  of  habit. 

Street,  J.  R.  :  A  Study  in  Language  Teaching.     Ihid.^  April,  1897, 
Vol.  4,  pp.  269-293. 

Studies  in  School  Hygiene. 

BuRNHAM,   Wm.    H.  :    Outlines   of   School   Hygiene.     Ibid..,  June, 
1892,  Vol.  2,  pp.  9-71. 

Includes,  besides  a  general  survey  of  school  sanitation,  brief  studies 
of  such  topics  as  fatigue,  the  period  of  study,  school  furniture,  the 
hygiene  of  writing,  etc. 

BuRNHAM,   Wm.    H.  :    Bibliography  of  School  Hygiene.     Proc.  iV. 
E.  A.,  1898,  pp.  505-523. 
A  selected  list  of  436  titles. 

Chrisman,  Oscar:    The  Hearing  of  Children.     Pedagogical  Semi- 
nary, Dec,  1893,  Vol.  2,  pp.  397-441. 

A  resume  of  the  investigations  of  the  hearing  of  school  children  in 
different  countries.  Practically  complete  to  the  date  of  publication,  with 
practical  suggestions  collected  from  different  authorities. 


Pedagogy.  167 

Dkesslae,  F.  B.  :  Fatigue.     Ibid.,  June,  1892,  Vol.  2,  pp.  102-106. 
An  introduction  to  tlie  general  subject  of  mental  fatigue. 

Dkesslae,  F.  B.  :  A  Sketch  of  Old  Schoolhouses.  lUd.^  June, 
1892,  Vol.  2,  pp.  115-125. 

A  brief  historical  contribution  to  school  hygiene. 

Principles,  Methods,  and  Organization  of  Education. 

Croswell,  T.  li.  :  Courses  of  Study  in  the  Elementary  Schools  of 
the  United  States.     Ibid.,  April,  1897,  Vol.  4,  pp.  294-335. 

Devoted  especially  to  state  and  city  courses  and  legal  requirements. 

Ellis,  A.  Caswell  :  Suggestions  for  a  Philosophy  of  Education. 
Ibid.,  Oct.,  1897,  Vol.  5,  pp.  159-201. 

The  closing  chapter  of  an  extended  historical  study  of  the  philosophy 
of  education  presented  as  a  dissertation. 

Hall,  G.  Stanley  :  Child  Study  the  Basis  of  Exact  Education. 
Forum,  Dec,  1893,  Vol.  16,  pp.  429-441. 

LuKENS,  Heemaist  T.  :  The  Correlation  of  Studies.  Educational  Re- 
view, Nov.,  1895,  Vol.  10,  pp.  364-383. 

PoTTEE,  J.  R.  :  History  of  Methods  of  Instruction  in  Geography. 
Pedagogical  Seminary,  Dec,  1891,  Vol.  1,  pp.  415-424. 

Specially  an  account  of  German  methods,  based  upon  literature. 

ScRiPTUEE,  E.  W.  :  Education  as  a  Science.  Ibid.,  June,  1892, 
Vol.  2,  pp.  111-114. 

A  plea  for  experimental  education  with  report  of  illustrative  experi- 
ments. 

Seaes,  Chaeles  H.  :  Home  and  School  Punishments.  7S/t?.,  March, 
1899,  Vol.  6,  pp.  159-187. 

Based  upon  literature  and  the  answers  to  a  questionnaire. 

The  Training  of  Teachers. 

BuEK,  Feedeeick  L.  :  The  Training  of  Teachers.  Atlantic  Monthly.^ 
Oct.,  1897,  Vol.  80,  pp.  547-561,  and  June,  1898,  Vol.  81,  pp. 
769-779. 


168  Pedagogy. 

Btjrnham,  Wm.  H.  :  Higher  Pedagogical  Seminaries  in  Germany. 
Pedagogical  Seminary,  Dec.,  1891,  Vol.  1,  pp.  390-408. 

A  sketch  of  the  history  and  present  character  of  the  different  kinds 
of  pedagogical  seminaries  for  training  teachers  for  the  higher  schools  in 
Germany,  based  on  literature  and  personal  observation. 

BuKNHAM,    Wm.   H.  :    Some   Aspects   of  the   Teaching  Profession. 
Forum,  June,  1898,  Vol.  25,  pp.  481-495. 

Hall,  G.  Stanley  :  American  Universities  and  the  Training  of 
Teachers.  Ihid.,  April  and  May,  1894,  Vol.  17,  pp.  148-159, 
297-309. 

Hall,  G.  Stanley:  The  Training  of  Teachers.  75ic2.,  Sept.,  1890, 
Vol.  10,  pp.  11-22. 

Hall,  G.  Stanley  :  Research  the  Vital  Spirit  of  Teaching.  Ihid.^ 
July,  1894,  Vol.  17,  pp.  558-570. 

Phillips,  D.  E.  :  The  Teaching  Instinct.  Pedagogical  Seminary^ 
March,  1899,  Vol.  6,  pp.  188-245. 

A  study  of  the  phenomena  of  leadership  and  teaching  among  animals 
and  children,  of  the  lives  and  motives  of  the  great  teachers,  and  of  train- 
ing in  relation  to  the  teaching  instinct,  including  a  contribution  by  the 
questionnaire  method.     Presented  as  a  dissertation. 

Reigaet,  J.  F.  :  The  Training  of  Teachers  in  England.  Ibid.,  Dec, 
1891,  Vol.  1,  pp.  409-415. 

A  brief  sketch  based  upon  literature. 

Miscellaneous. 

BuRK,  Fredeeick  L.  :  Teasing  and  Bullying.    Pedagogical  Seminary, 
April,  1897,  Vol.  4,  pp.  336-371. 
Based  on  returns  to  a  questionnaire. 

Hall,  G.  Stanley  :  Boy  Life  in  a  Massachusetts  Country  Town 
Thirty  Years  Ago.  Proe.  Am.  Antiq.  Soe.,  Worcester,  Mass.,  Oct. 
21,  1890,  N.  S.,  Vol.  7,  pp.  107-128. 

An  historical  contribution  showing  the  many-sidedness  of  the  home 
education  of  the  New  England  country  boy. 


Pedagogy.  169 

Hall,  G.  Stanley:  The  Case  of  the  Public  Schools.  Atlantic 
Montlily,  March,  1896,  Vol.  77,  pp.  402-413. 

Hall,  G.  Stanley  :  The  Love  and  Study  of  Nature :  a  Part  of 
Education.  Agriculture  of  Massachusetts,  1898,  pp.  134-154. 
Lectures  delivered  before  the  Massachusetts  State  Board  of  Agri- 
culture at  Amherst,  Dec.  6,  1898. 

Treats  of  the  child's  attitude  toward  nature. 

Hancock,  John  A.  :  An  Early  Phase  of  the  Manual  Training  Move- 
ment.    Ihid.,  Oct.,  1897,  Vol.  5,  pp.  287-292. 

A  brief  historical  sketch  of  the  old  manual  labor  school. 

Johnson,  G.  E.  :  Contribution  to  the  Psychology  and  Pedagogy  of 
Feeble-minded  Children.     Ihid.,  Oct.,  1895,  Vol.  3,  pp.  246-291. 

Reports  result  of  tests  of  memory  span,  motor  ability,  and  association, 
in  feeble-minded  children  at  the  Massachusetts  School  for  the  Feeble- 
minded at  Waltham,  together  with  an  historical  introduction  and  practi- 
cal suggestions  for  their  education. 

KiSTLER,  Milton  S.  :  John  Knox's  Services  to  Education.  Education, 
Oct.,  1898,  Vol.  19,  pp.  105-116. 

Kline,  Linus  W.  :  Truancy  as  Related  to  the  Migratory  Instinct. 
Pedagogical  Seminary,  Jan.,  1898,  Vol.  5,  pp.  381-420. 

Includes  a  comparison  of  the  physical  condition  of  truants  as  shown 
by  anthropometric  tests  with  that  of  public  school  children. 

Sheldon,  Henry  D.  :  The  Institutional  Activities  of  American  Chil- 
dren.    Am.  Jour,  of  Psy.,  July,  1898,  Vol.  9,  pp.  425-448. 
Based  largely  on  returns  to  a  questionnaire. 

Small,  M.  H.  :  Methods  of  manifesting  the  Instinct  for  Certainty. 
Pedagogical  Seminary,  Jan.,  1898,  Vol.  5,  pp.  313-380. 

A  comprehensive  study  of  oaths  based  upon  2,263  answers  to  a  ques- 
tionnaire and  a  vast  amount  of  literature. 

Such  have  been  the  methods  of  the  department,  and  such  in  part  the 
work  done.     The  aim  has  been  to  treat  a  few  subjects  in  a  broad  way, 


170  Pedagogy. 

rather  than  to  exhaust  the  fiekl  of  conventional  pedagogy.  The  necessity 
and  the  advantages  of  this  method  are  obvious  from  a  brief  consideration 
of  the  subject  of  education,  both  theoretical  and  practical. 

Jean  Paul  Richter  quotes  the  French  artist  who  required  from  a  good 
director  of  the  ballet,  besides  the  art  of  dancing,  only  geometry,  music, 
poetry,  painting,  and  anatomy.  "  But,"  he  adds,  "  to  write  upon  educa- 
tion means  to  write  upon  almost  everything  at  once  ;  for  it  has  to  care  for 
and  watch  over  the  development  of  an  entire  .  .  .  world  in  little,  —  a 
microcosm  of  the  macrocosm.  ...  If  we  carried  the  subject  still  fur- 
ther, every  century,  every  nation,  and  even  every  boy  and  every  girl, 
would  require  a  distinct  system  of  education,  a  different  primer  and  do- 
mestic French  governess,  etc."^  The  subject  of  pedagogy  is  still  more 
encyclopaedic  to-day  than  when  Jean  Paul  Richter  wrote  these  words. 
Its  foundation  involves  the  whole  physiology  and  psychology  of  develop- 
ment in  the  individual,  and  the  history  of  culture  in  the  race,  and  its 
superstructure  includes,  not  only  all  the  various  forms  and  systems  and 
methods  of  education,  but  the  study  of  the  influence  of  environment  in 
the  widest  sense. 

The  conventional  views  minimize  both  the  difficulties  and  the  impor- 
tance of  the  subject.  It  is  said  that  pedagogy  is  applied  psychology  or 
applied  child  study,  and  again  that  pedagogy  must  get  its  norms  from  the 
history  of  education  and  from  child  study.  This  statement  will  do  if  one 
knows  what  it  involves.  The  history  of  education  means  the  history  of 
civilization  from  its  earliest  traceable  genesis  among  primitive  peoples. 
It  means  a  study  of  types  of  culture  and  the  conditions  of  their  develop- 
ment. In  a  word,  it  is  a  study  of  the  evolution  of  education.  Child 
study  means,  too,  the  study  of  the  physiology  and  psychology  of  develop- 
ment in  man.  The  science  of  development  aims  to  give  a  complete 
description  of  all  the  stages  of  phj'sical  development  from  infancy  to 
maturity,  to  show  their  sequence  and  their  relation  to  the  acquisition  of 
organic,  sensory,  motor,  and  psychic  processes.  As  far  as  psychology  goes, 
it  is  genetic  psychology,  which  means  more  than  is  frequently  connoted 
by  child  study.  Adult  psychology  is  one  thing,  relatively  fixed,  except 
for  variations  incident  to  environment  or  the  individual.  Child  psychol- 
ogy, even  for  a  single  individual  and  a  given  environment,  varies  con- 
tinually because  the  individual  is  in  the  process  of  growth  and  rapid 
development  of  function.     It  is  one  thing  for  the  infant,  a  very  different 

1  Richter,  "  Levana,  or  the  Doctrine  of  Educatiou,"  Author's  Preface. 


Pedagogy.  171 

thing  for  the  child  who  can  walk  and  talk,  still  another  at  that  plateau  in 
the  curve  of  development  that  seems  to  come  somewhere  between  nine 
and  twelve  for  girls  and  ten  and  fourteen  for  boys,  still  another  for  the 
adolescent.  The  variation  is  seen  in  the  period  of  a  single  year,  almost 
with  the  changing  moons.  This  is  true,  not  only  on  account  of  the  grosser 
acquisitions,  but  is  seen  in  the  sequence  of  interests  and  activities.  Cliild 
psychology  is  protean.  It  varies  not  only  with  the  individual  and  the 
environment,  but  especially  with  the  stage  of  development.  Further,  the 
science  of  development  includes  comparative  psychology.  Not  only  must 
the  child  mind  be  compared  with  the  adult  mind,  but  the  stages  of  devel- 
opment in  the  child  should  be  compared  with  the  stages  of  development  in 
animals,  the  faculties  of  the  child  with  those  in  animals,  the  motor  ability 
and  activities  of  the  child  with  those  in  animals.  And  again,  the  stages 
of  development  in  the  child  must  be  compared  with  those  in  the  race; 
ontogenesis  in  relation  to  phylogenesis  must  be  studied. 

All  this  is  scientific  study,  not  directly  practical.  Before  deriving  the 
norms  for  practical  pedagogy,  a  propaedeutic  study  must  be  made.  As 
Professor  James  has  said:  "  Psychology  is  a  science,  and  teaching  is  an 
art ;  and  sciences  never  generate  arts  directly  out  of  themselves.  An 
intermediary  inventive  mind  must  make  the  application  by  using  its 
originality."  This  mediating  function  is  represented  by  two  somewhat 
vaguely  defined  branches  of  pedagogy  —  educational  psychology,  and  the 
general  principles  and  methods  of  education. 

Again,  after  the  general  principles  of  education  have  been  derived  from 
psychology  and  history,  and  the  theoretical  norms  established,  they  must 
be  verified  by  practical  educational  experiments.  This  brings  us  to  the 
practical  side  of  pedagogy  represented  by  such  subjects  as  the  organiza- 
tion of  schools,  the  art  of  teaching,  and  special  didactics.  And  parallel 
with  the  art  of  teaching  in  its  derivation  from  the  science  of  development 
is  school  hygiene,  which  studies  especially  the  conditions  that  favor  the 
healthy  development  of  the  school  child.  Thus  pedagogy  is  both  theoreti- 
cal and  practical,  at  once  a  science  (at  least  potentially)  and  an  art. 

Such  is  the  subject  which,  as  the  Italian  proverb  runs,  is  always  poor 
and  naked,  and,  in  the  words  of  a  German  writer,  has  long  sat  as  a  drudge 
at  the  academic  hearth,  and  whose  highest  recognition  in  the  great  univer- 
sities has  usually  been  as  the  handmaid  of  philosophy.  Everybody 
believes  in  education,  yet  few  believe  in  pedagogy.  The  reasons  for  this 
are  obvious.     Apart  from  a  few  fundamentals  that  are  almost  common- 


172  Pedajogy. 

place,  pedagogy  has  lacked  a  solid  body  of  scientific  knowledge  and 
universally  accepted  principles.  Worse  than  this,  it  has  lacked  a  definite 
method  and  a  definite  ignorance. 

Most  of  the  works  on  the  history  of  education  are  padded  with  accounts 
of  second-rate  writers  and  second-rate  books  that  happen  to  be  labelled 
educational ;  while  the  really  great  educators  have  often  been  neglected, 
and  educational  movements  have  been  described  as  isolated  currents  in 
the  progress  of  civilization,  without  regard  to  their  vital  connection  with 
political,  social,  and  industrial  movements.  The  method  has  been  the 
elementary  method  of  studying  and  describing  isolated  facts  without 
regard  to  historical  perspective  and  causal  relations;  and  even  the  works 
of  the  classic  writers  have  been  chiefly  the  repetition  and  recasting  of  a 
few  old  truths  which  had  been  forgotten  or  were  ignored  at  the  time  in 
which  the  reformers  lived.  For  example,  Comenius  two  hundred  and  fifty 
years  ago  taught  that  we  must  study  nature  by  the  inductive  method 
and  adapt  education  to  the  sequence  of  the  stages  of  natural  development; 
but  his  writings  were  forgotten,  and  again  and  again  the  reformers  have 
had  to  teach  again  to  a  new  generation  the  simplest  principles  of  the 
Comenian  didactic.  Most  of  the  books  on  the  educational  systems  of 
to-day,  in  like  manner,  consist  of  the  barren  details  of  organization  and 
method,  and  the  description  often  of  inferior  teachers  and  schools.  The 
forces  that  have  produced  these  teachers  and  schools,  the  significance  of 
the  educational  movements,  have  not  been  seen;  and  the  philosophical, 
social,  and  religious  thought  that  has  determined  educational  ideals  has 
not  been  studied.  These  isolated  facts  are  barren.  Their  real  signifi- 
cance is  in  their  relation  to  other  facts.  We  cannot,  for  example,  under- 
stand the  educational  events  in  England  to-day  unless  we  know  something 
of  the  wider  relations  of  the  school  movement.  The  wrangling  over  the 
question  whether  the  parish  of  Eastbourne  shall  have  a  school  board, 
or  whether  the  school  education  of  the  parish  shall  continue  to  be  supplied 
by  voluntary  schools,  means  a  great  deal  more  than  a  difference  in  taxes 
of  a  few  pence  in  the  pound.  This  petty  struggle  is  a  part  of  the  great 
movement  for  the  disestablishment  of  the  Church  of  England.  The  com- 
missioning of  a  new  fellow  for  university  extension  work  marks  another 
step  in  the  progress  of  the  democratic  ideal,  which,  no  longer  satisfied  with 
provision  for  elementary  education  for  every  child,  now  demands  also  for 
each  individual,  according  to  his  ability,  a  share  in  higher  education.  A 
new  endowment  for  a  technical  school  by  the  Worshipful  Society  of  Gold- 


Pedagogy.  173 

smiths,  or  the  like,  may  indicate  a  new  dread  of  democracy  on  the  part  of 
certain  monopolists  quite  as  much  as  any  special  interest  in  industrial 
education.  Oxford  itself,  with  all  its  marvellous  beauty  and  idealism,  the 
stronghold  of  conservatism,  cannot  keep  aloof  from  the  great  social,  indus- 
trial, and  educational  movements  outside.  No  better  illustration  could  be 
chosen  to  show  the  progress  of  the  democratic  ideal  in  education.  At  the 
beginning  of  Queen  Victoria's  reign  one  could  not  even  study  at  Oxford 
without  subscribing  to  the  Thirty-nine  Articles.  A  few  years  ago  Jowett 
advocated  opening  the  university  honors  and  emoluments  to  the  world, 
admitting  anybody  to  any  university  examination  without  restriction  of 
sect,  class,  race,  age,  or  residence.  As  was  remarked  at  the  time,  if  fifty 
or  perhaps  twenty  years  ago  a  radical  undergraduate  were  to  have  made 
such  suggestions,  he  would  have  stood  a  chance  of  being  expelled  from  the 
university,  as  Shelley  was,  for  blasphemy;  now  they  are  the  last  words 
of  Jowett,  quoted  with  approval  before  the  vice-chancellor. 

To  miss  these  larger  aspects  is  to  miss  everything  of  permanent  value. 
Historical  literature  in  education  has  relatively  little  importance  for  its 
direct  practical  teachings ;  but  the  importance  of  the  history  of  education 
as  a  culture  subject  can  hardly  be  put  too  high.  Education  represents 
one  of  the  deepest  human  interests,  more  vital  than  politics,  and  well- 
nigh  as  universal  as  religion.  The  history  of  education  is  the  history  of 
the  development  of  civilization.  It  aims  at  nothing  less  than  the  study 
of  the  school  as  a  factor  in  the  development  of  culture  in  relation  to  the 
other  factors  in  education,  —  the  home,  the  church,  the  farm,  the  work- 
shop, the  playground,  and  the  rest.  And  it  aims  at  the  study  of  educa- 
tional movements  in  their  genesis,  and  in  relation  to  political,  social, 
industrial,  scientific,  and  literary  movements.  This  involves  not  merely 
the  study  of  educational  writers  so-called  and  school  systems,  but  the 
study  of  types  of  culture  and  the  causes  that  condition  them. 

Likewise  in  the  other  parts  of  the  field  the  failure  to  recognize  the 
wider  significance  of  the  subjects  studied,  and  the  attempt  to  build  sys- 
tems before  the  foundations  were  laid,  have  brought  pedagogy  into  disre- 
pute. But  in  recent  years  the  conviction  has  grown  that  educational 
problems  must  be  studied  inductively  ;  and,  better  still,  important  contri- 
butions by  the  inductive  method  have  actually  been  made.  This  has  put 
life  into  the  subject  and  given  hope  for  the  future.  Take  child  study  as 
an  illustration.  The  significance  of  the  modern  study  of  children  is  not 
merely  the  renewed  emphasis  on  the  old  truth  of  adapting  education  to 


174  Pedagogy. 

the  stages  of  development,  but  the  insight  that  the  only  way  to  make  this 
principle  vital  is  concrete  inductive  study  to  find  out  just  what  are  the 
stages  of  natural  development.  Thus  every  fact  in  regard  to  general 
development  or  individual  variation  is  deemed  significant,  and  the  student 
is  willing  to  wait  for  a  new  science  of  development  before  attempting  a 
permanent  pedagogical  system. 

During  the  past  ten  years  the  opportunities  for  truly  scientific  work 
in  education  have  been  shown  as  never  before,  methods  of  investigation 
have  been  demonstrated,  and  in  part  the  foundations  of  a  science  have 
been  laid.  The  things  now  needed  are  trained  men  and  facilities.  With 
them  a  solid  content  of  scientific  knowledge  can  be  acquired  that  will 
place  historical  and  social  pedagogy  on  as  firm  a  basis  as  general  history 
and  sociology,  and  genetic  pedagogy  on  a  scientific  footing  comparable  to 
that  of  psychology.  School  hygiene  has  already  its  methods  and  a  solid 
body  of  knowledge,  but  it  needs  special  laboratories  for  instruction  and 
research,  either  independent  or  in  connection  with  psychology,  physiology, 
and  anthropology. 

The  work  in  pedagogy  in  this  University,  although  the  practical 
aspects  of  the  subjects  studied  have  not  been  neglected,  has  been  chiefly 
in  the  more  scientific  and  theoretical  parts  of  the  field.  It  is  not  less 
important  on  this  account.  Pedagogical  study,  like  research  in  any 
other  field  of  history  or  science,  is  valuable  for  its  own  sake  without 
regard  primarily  to  practical  results.  It  is  its  own  justification  and  its 
own  reward.  With  the  nucleus  of  solid  scientific  contributions  that  now 
exists,  no  university  can  long  afford  to  omit  courses  in  education  from  its 
curriculum,  whether  they  have  any  practical  value  or  not.  Such  scien- 
tific studies,  however,  cannot  be  divorced  from  the  practical  art  of  educa- 
tion. The  studies  of  children  have  emphasized  the  doctrine  that  the  aim 
of  childhood  is  its  own  development,  and  the  best  guarantee  of  normal 
maturity  is  normal  childhood  and  immaturity  ;  in  a  word,  they  have 
emphasized  the  principles  of  normal  development.  But  these  principles 
are  no  longer  pedagogical  abstractions  ;  they  are  greatly  modifying  the 
practical  work  of  education,  causing  greater  regard  for  individual  chil- 
dren rather  than  uniform  classes,  for  health  rather  than  scholastic  prod- 
ucts, for  a  psychological  order  of  instruction  adapted  to  the  capacity  and 
interests  of  children  rather  than  logical  sequence  and  articulation  of 
grades.  In  a  word,  they  are  causing  courses  of  study  and  methods  to  be 
reconstructed  with  regard  to  the  one  fundamental  principle  of  fostering 


Pedagogy.  175 

normal  growth  and  development.  To  mention  a  few  details,  ten  years 
ago  school  baths,  adjustable  seats  and  desks,  and  vertical  script,  were 
vagaries  of  university  theorists  ;  to-day  they  are  deemed  essentials  in 
the  best  schools.  Ten  years  ago  suggestions  of  periodic  disinfection  of 
school  apparatus  and  school  text-books,  of  investigating  pupils'  individual 
capacity  and  power  to  resist  fatigue,  and  of  adapting  education  to  indi- 
vidual capacity  and  interest,  in  elementary  and  secondary  schools,  were 
likely  to  be  ridiculed  ;  now  their  soundness  has  been  demonstrated  by 
practical  experiments. 

What  part  this  University  has  had  in  this  movement,  it  is  not  easy 
to  say ;  but  it  has  always  advocated  such  reforms  in  the  regular  courses 
of  lectures  ;  many  addresses  on  topics  in  school  hygiene  and  pedagogy  have 
been  given  outside  the  University  before  schools  and  teachers'  meetings ; 
students  from  this  University  have  become  school  superintendents,  teachers 
in  secondary  schools,  professors  of  pedagogy  or  psychology  in  normal 
schools,  professors  of  pedagogy  in  colleges  and  universities  ;  and  teachers 
and  educators  from  all  parts  of  the  country  have  attended  lectures  on 
pedagogy  during  the  sessions  of  the  Summer  School. 

To  make  a  department  of  pedagogy  what  it  should  be,  it  is  necessary 
that  the  whole  field  of  education  be  covered  by  lectures  as  far  as  possible, 
that  the  more  elementary  courses  be  given  every  year,  that  research 
should  be  extended  to  the  multitude  of  topics  that  offer  opportunity 
for  study.  Nowhere  in  the  world  is  a  complete  course  in  pedagogy 
covering  all  the  important  parts  of  the  field  given.  Here  and  there 
throughout  this  country  and  Europe  are  offered  a  few  truly  scientific 
courses,  but  the  subject  will  hardly  attain  its  due  academic  dignity  until 
somewhere  in  one  university  are  given  courses  which  approximate  an 
adequate  treatment  of  the  whole  field.  That  this  University  might 
approximate  a  complete  course  in  the  subject  are  needed  an  addition  to 
the  staff,  especially  for  the  study  of  historical  and  social  pedagogy,  the 
establishment  of  special  fellowships  for  educational  research,  a  laboratory 
for  school  anthropometry  and  school  hygiene,  a  great  enlargement  of  the 
educational  museum,  a  pedagogical  library  like  that  of  the  Musee  peda- 
gogiqne  in  Paris,  where  educational  literature  of  every  kind,  both  good 
and  bad,  may  be  collected ;  and,  finally,  a  model  school  for  the  objectifi- 
cation  of  ideals,  under  the  direction  of  competent  teachers  who  should 
safeguard  the  interests  of  the  pupils,  but  offer  to  university  students  op- 
portunities for  observation,  and  in  some  cases  for  practice  in  school  work. 


176  Pedagogy. 

The  aim  of  such  a  course  in  pedagogy,  like  that  of  the  more  limited 
course  already  given  in  this  University,  would  be  twofold  :  first,  to  con- 
tribute something  to  the  body  of  knowledge  in  regard  to  education,  the 
content  of  pedagogy  ;  and,  second,  to  give  practical  training  to  students 
preparing  to  become  teachers.  These  two  aims  are  quite  in  harmony, 
for  an  essential  in  the  training  of  a  teacher  is  the  development  of  those 
permanent  professional  interests  and  that  professional  apperception  and 
prevision  acquired  by  the  study  of  the  more  scientific  parts  of  pedagogy. 


PHILOSOPHY. 

By  G.  Stanley  Hall. 

In  addition  to  my  own  work  in  psychology  and  education,  reported 
in  the  preceding  articles  by  my  colleagues,  Drs.  Sanford  and  Burnham, 
and  in  editing  the  American  Journal  of  Psychology  and  the  Pedagogical 
Seminary,  I  have  lectured  during  the  last  eight  years  on  the  History  of 
Philosophy.  This  course  is  felt  to  be  of  cardinal  importance  for  those 
studying  either  psychology  or  education,  to  give  them  breadth  of  view, 
to  teach  what  great  problems  have  interested  the  race,  and  to  give  a 
repertory  of  general  ideas  that  will  obviate  some  of  the  dangers  of 
specialization. 

The  course  begins  with  a  very  brief  survey  of  Oriental  speculation, 
treats  the  pre-Socratic  Greek  thinkers  with  considerable  detail  and  with 
constant  reference  to  their  fragmentary  texts.  Great  stress  is  laid  upon 
Plato,  and  from  a  quarter  to  half  of  all  his  works  are  read  aloud  by  the 
students  in  turn  from  Jowett's  translation,  and  on  these  dialogues  the 
examination  for  the  doctorate  is  in  some  part  based.  Even  for  those 
who  read  some  Greek,  the  use  of  the  English  translation  is  preferred, 
because  more  can  be  gained  from  Plato  by  men  of  this  grade  by  extensive 
reading  than  by  intensive  and  critical  study  of  text.  Discussions  often 
arise  in  this  work.  Aristotle  is  treated  in  the  same  manner,  and  selec- 
tions and  sometimes  large  portions  of  some  of  his  works  are  read  in 
English.  From  twelve  to  twenty  lectures  are  given  on  the  later  schools, 
ending  with  Plotenus  and  Proclus.  This  usually  concludes  the  work  of 
the  first  year. 

Until  two  years  ago  the  second  year  began  with  the  rise  of  scholasti- 
cism and  the  third  ended  with  Schopenhauer,  Lotze,  Hartmann,  and  con- 
temporary writers.  Special  effort  has  always  been  made  to  go  considerably 
outside  the  stock  text-book  field  and  to  deal  to  some  extent  with  the 
history  of  science,  with  some  reference  to  medicine  and  with  very  slight 
reference  to  literature,  art,  etc.  The  texts  of  Spinoza,  Locke,  Berkeley, 
N  177 


178  Pliilosoijliy. 

i 

Hume,  Kant,  Fichte,  Schelling,  Hegel,  Schopenhauer,  and  Lotze  have 
been  used  at  different  times  and  with  very  different  results.  Ethics, 
logic,  metaphysics,  and  esthetics  are  included  in  this  course,  and  no 
special  courses  in  any  of  these  subjects  have  been  given,  although  logical 
and  ethical  questions  are  treated  in  my  psychological  course.  Considera- 
ble time  is  always  given  to  epistemology. 

Two  years  ago,  after  considerable  previous  preparation,  a  course  in 
Christology  and  Patristics  was  inserted  between  the  ancient  and  the  mod- 
ern course  as  above  described.  The  life  of  Jesus  was  treated  concisely 
and  reverently  from  the  standpoint  of  psychology,  which  is  felt  to  be  very 
different  from  that  of  the  current  lives  of  Jesus.  This  course,  although 
at  present  being  repeated  with  amplification,  is  still  too  incomplete  to 
warrant  any  final  report  upon  its  utility.  On  the  whole  this  historic 
course,  which  occupies  three  years,  is  earnestly  recommended  to  all  stu- 
dents of  psychology,  religion,  education,  or  any  of  the  humanities,  and 
has  generally  been  taken  by  all. 

During  the  past  eight  years  I  have  opened  my  house  one  evening 
every  week  of  the  academic  year  to  all  students  in  the  department  of 
psychology  and  related  themes  from  seven  to  ten  o'clock.  We  began 
by  discussing  philosophical  topics  assigned  beforehand  to  leaders  in  turn. 
One  year  most  of  the  time  of  tliis  seminary  was  devoted  to  reading 
and  discussing  Jowett's  Plato. ^  Schopenhauer,  Kant,  and  Hegel  were 
tried  for  briefer  periods,  but  gradually,  as  the  numbers  have  increased 
and  as  the  rule  that  each  man  should  devote  a  portion  of  his  time  to  some 
original  investigation  has  prevailed,  the  evening  has  been  occupied  by 
each  student  in  turn,  who  presents  his  thesis  or  subject,  or  a  part  of  it, 
which  is  then  freely  discussed  by  the  other  members.  The  debates  are 
often  animated,  as  nearly  every  standpoint  is  represented.  There  are 
clergymen,  young  professors  from  other  institutions,  Hegelian  idealists, 
Kantian  epistemologists,  and  men  of  empirical  science,  and  from  these 
various  directions  nearly  every  subject  is  really  illuminated.  Attendance 
is  never  enforced,  and  the  light  refreshments  served  in  the  middle  of  the 
evening  have  never  been  an  attraction,  but  only  a  welcome  break  from 
continued  tension.     The  attendance  for  the  last  few  years  has  rarely  been 

1  See  a  somewhat  disguised  account  of  the  first  semester's  work  in  two  articles  by  H. 
Austin  Aikins,  entitled  "From  the  Reports  of  the  Plato  Club."  Atlantic  Monthly,  Sept. 
and  Oct.,  1894,  Vol.  74,  pp.  359-368,  470-480. 


Philosophy.  179 

under  fifteen  and  rarely  over  forty,  so  that  the  entire  freedom  and  infor- 
mality of  conversation  has  been  the  rule.  The  themes  assigned  in  a  way 
described  later  have  been  presented  here  in  so  compact  and  forcible  a 
way,  that  the  seminary  has  been  one  of  the  most  effective  agents  in  my 
own  education,  and  I  think  all  its  members  share  my  sentiments  in  this 
respect.  Here  the  new  work  on  which  each  individual  is  spending  so 
much  of  his  year's  time  is  pooled  for  the  common  benefit,  the  reader  has 
the  healthful  stimulus  of  emulation  in  interesting  his  audience,  acquires 
valuable  practice  in  the  methods  of  effective  presentation,  and  always 
receives  help  in  the  way  of  new  literature,  references,  the  pointing  out 
of  defects  in  argument  or  method  ;  and  conflicts  are  thus  most  surely 
avoided.  Often  other  professors  from  the  University  attend,  and  the  list 
of  distinguished  guests  from  abroad  who  have  either  participated  in  the 
discussions  or  introduced  matter  of  their  own  is  a  long  and  dignified  one. 
There  is  rarely  any  lack  of  interest  or  reluctance  to  discuss,  and  very 
infrequently  is  the  animation  too  great  for  healthful  mental  circulation. 
Here  nearly  everything  that  has  been  done  by  the  student  members  of 
this  department  of  the  University  has  been  carefully  wrought  over,  some 
of  it  more  than  once. 

Such  stimulus  I  believe  to  be  unsurpassed  in  educational  value.  The 
dialectic  give  and  take  of  the  conversational  method,  the  mental  alertness 
of  debate,  the  charm  of  friendly  intercourse  upon  high  themes,  which 
Lotze,  like  some  of  the  ancients,  thought  the  highest  joy  of  life  and  the 
consummate  fruition  of  friendship,  are  here  combined  in  judicious  propor- 
tions most  favorable  to  growth.  Some  European  seminaries  are  devoted 
to  discussions  of  minute  points  ;  in  others  the  student  is  simply  a  literary 
forager  for  the  professors  ;  quite  frequently  some  author  is  read ;  but  for 
our  American  needs,  at  least  for  Clark  University,  I  think  the  method 
now  settled  upon  is  more  educative  than  any  other  that  I  have  seen. 

A  word  should  be  said  concerning  student  lectures.  At  various 
periods  during  the  decade  each  member  of  the  department  has  been 
requested  to  take  his  turn  in  presenting  some  subject  in  due  form  before 
the  class,  taking  my  place  at  the  lecturer's  desk,  and  developing  his  theme 
with  the  aid  of  charts,  blackboard,  and  specimens  if  need  be;  and  at 
the  close  of  the  lecture  I  have  a  personal  interview,  stating  very  frankly 
any  faults  of  manner,  automatism,  voice,  method  of  presentation,  etc., 
liable  to  interfere  with  his  usefulness  as  instructor  or  lecturer.     More 


180  Philosophy. 

often,  in  place  of  an  original  lecture,  each  man  takes  his  turn  in  digesting 
with  extracts  some  book  or  chapter  of  a  standard  work  in  the  history 
of  philosophy,  with  the  same  criticisms.  This  personal  relation  together 
with  the  many  hours  spent  each  week  with  individuals,  elsewhere  spoken 
of,  has  been,  I  believe,  of  great  value. 

At  the  beginning  of  the  year  (or,  for  those  who  have  already  spent  a 
year  at  the  University,  near  the  close  of  the  spring  term)  careful  lists  of 
subjects  which  seem  to  the  instructors  in  the  department  ripe  for  investi- 
gation are  prepared.  Each  jots  down  all  suggestions  in  this  direction 
during  the  year,  and  all  now  meet  to  compare  themes,  consider  whether 
they  have  already  been  treated,  what  new  books  and  apparatus  each  will 
necessitate,  by  what  paths  each  can  best  be  approached  and  which  are 
likely  to  yield  the  best  and  (what  for  thesis  work  is  of  great  impor- 
tance) the  most  certain  results  of  value.  Conferences  with  each  indi- 
vidual are  then  held  and  each  is  urged  to  select  some  theme,  either 
because  it  is  congenial  or  because  it  represents  a  field  he  desires  to  enter, 
and  to  devote  some  considerable  portion  of  the  year  to  the  effort  to 
master  it  and  to  add  something  new,  however  small,  to  the  sum  of  the 
world's  knowledge. 

A  really  good  subject  has  aspects  or  divisions  that  bring  the  student 
into  contact  with  each  professor  in  the  department,  and  each  gives 
everything  in  the  way  of  information,  stimulus,  and  references  that  he 
possibly  can.  Our  plan  has  always  been  to  allow  the  student  to  print 
such  work  over  his  own  name  and  to  have  full  credit,  although  he  usually 
makes  acknowledgements  at  the  close  of  his  paper  to  his  helpers.  This 
plan  we  have  found  very  congenial  and  stimulating  to  students,  and  it 
has  avoided  all  questions  of  ownership  rights  in  intellectual  property. 
Again,  a  good  subject  must  be  midway  between  a  very  large  and  general 
and  a  very  minutely  special  standpoint.  The  student  must  not  waste  his 
energy  in  vague  generalities  on  the  one  hand,  nor  must  he  be  shut  up  to 
some  petty  problem,  perhaps  fitting  into  and  aiding  the  professor's  special 
work,  being  thus  unduly  subordinated  and  apprenticed  to  him,  as  is  so 
common  in  Germany.  Fitting  the  problem  to  the  man  so  that  it  will 
enlist  all  his  interest  and  focus  his  knowledge  and  effort  is  half  the  work. 

In  beginning  more  or  less  independent  research  like  this,  our  best 
college  graduates  are  often  in  a  sense  suddenly  reduced  back  to  infancy 
and  need  constant  individual  help  to  go  alone.     For  the  last  ten  years 


PJiilosophy.  181 

most  of  several  afternoons  a  week  of  my  own  time  has  been  given  in  the 
laboratory,  library,  and  conference  room  in  trying  to  assist  and  direct 
young  men  to  launch  out  in  some  modest  yet  effective  way,  as  becomes 
them,  on  the  great  life  of  discovery.  Some,  often  the  best  scholars,  are 
so  tied  to  authority  that  it  is  hard  for  them  to  be  brought  to  realize  that 
the  best  things  have  neither  been  done  nor  said  in  the  world,  and  that 
mastery  of  the  text-book  is  not  final.  Others  are  strongly  inclined  to 
repeat  experiments,  multiply  observations,  and  accumulate  numbers,  and 
find  it  hard  to  make  a  serious  study  of  the  real  significance  of  their 
data.  Some  approach  subjects  with  preconceived  ideas  and  speculate 
in  a  deductive  way,  abhorring  details  which  others  get  lost  in.  Every 
type  of  philosophical  opinion  and  every  shade  of  temperament,  every  de- 
gree of  intellectual  enterprise  at  almost  every  rate  of  progress,  is  repre- 
sented. Some  are  strong  in  the  literary,  historical,  and  antiquarian  side 
of  their  topic ;  others  in  its  experimental  technique  or  in  statistical  pres- 
entation and  tabulation  or  in  literary  form ;  some  at  once  tend  to  lose 
themselves  in  aspects  of  the  subject  that  are  so  large  that,  instead  of  com- 
ing to  a  conclusion  in  an  academic  year,  they  begin  to  anxiously  plan  a 
life  work  and  anticipate  remote  difficulties;  while  others  can  see  abso- 
lutely nothing  in  topics  of  great  range  and  significance  except  some  over 
elaborately  fortified  or  proven  fact. 

This  form  of  modern  university  work  is  a  new  kind  of  high  Socratic 
midwifery,  but  in  my  opinion  it  is  the  most  beneficial  of  all  the  points 
of  contact  between  professor  and  student.  Some  must  be  encouraged; 
others  must  be  roundly  scolded.  Some  would  devote  all  their  time  to  an 
interesting  work  of  this  kind,  while  others  dawdle  with  it  as  a  mere  side 
issue  of  doubtful  educational  value.  A  few  do  not  want  it,  but  are  con- 
tented with  receptivity  of  what  others  have  done.  Restless  ones  often 
seek  change  of  theme,  so  that  great  discretion  and  great  patience  are 
needed  in  this  work. 

Its  rewards,  however,  are  incomparably  great.  Having  once  discov- 
ered a  fact  or  made  ever  so  small  an  original  contribution  and  had  the 
baptism  of  printer's  ink,  the  novitiate  is  henceforth  a  changed  man.  His 
ideals  of  culture,  standards  of  attainment  and  excellence,  and  his  methods 
of  work  are  slowly  revolutionized  from  this  centre.  Instead  of  being  a 
passive  recipient,  his  mind  has  tasted  a  free  and  creative  activity  which 
puts  him  on  his  mettle  like  the  first  taste  of  blood  to  a  young  tiger.  He 
has  learned  that  achievement  and  not  possession  is  the  end  and  aim ;  his 


182  Philoso2)liy. 

mind  has  been  brought  to  a  focus  in  such  a  way  that  he  now  knows  what 
real  concentration  means  as  never  before.  He  realizes  that  almost  every 
subject  in  the  universe,  if  broadly  seen,  is  connected  with  every  other,  and 
that  the  cosmos,  like  his  own  mind,  is  knit  together  into  a  unity  of  a 
higher  order.  In  all  his  works  and  ways  he  is  more  independent  and  more 
inclined  to  seek,  do,  know,  and  experience  for  himself.  By  such  personal 
conference  with  individuals  at  all  stages  of  their  preparation  in  such  a 
work,  which  need  not  be  a  doctor's  dissertation  and  often  is  not,  I  am  con- 
vinced, after  a  decade  of  experience  here  and  some  years  of  the  same  work 
at  the  Johns  Hopkins,  that  this  is  the  highest  criterion  of  an  academic 
teacher's  real  efficiency  in  his  vocation,  and  that  it  is  as  much  above  the 
mass  teaching  of  the  lecture-room  as  talent  is  above  mere  learning.  The 
necessity  of  this  work  is  one  of  the  chief  reasons  why  truly  university 
work  must  always  be  done,  if  not  at  small  institutions,  at  least  in  squads 
so  small  that  they  can  be  thus  individualized. 

Having  brought  this  work  to  some  degree  of  completion,  as  should  be 
done  at  the  close  of  each  academic  year,  even  at  some  sacrifice  of  scientific 
quality  (because  educational  values  should  take  precedence  even  over 
this,  where  the  two  conflict),  an  indispensable  requisite  is  publicity  and 
that  without  delay.  Any  institution  or  department  that  confers  a  doc- 
torate upon  the  ground  of  a  dissertation  that  is  unpublished  conceals  that 
upon  which  the  chief  value  of  the  degree  rests.  The  older  the  student 
the  more  stress  should  be  laid  upon  this  part  of  the  work  as  compared 
with  acquisition.  In  most  departments,  science  is  progressing  so  rapidly 
and  work  is  so  often  duplicated  that  the  necessity  of  announcing  before- 
hand the  theme  of  each  research  has  often  been  urged,  and  any  con- 
siderable interval  between  the  completion  of  a  work  and  its  publication 
involves  danger  of  anticipation  by  others,  as  well  as  general  loss  of  value 
from  the  progress  of  science,  which  is  always  slowly  leaving  everything 
behind.  Chiefly  to  avoid  this  danger  the  journals  of  this  University 
were  established,  in  which,  without  the  cost  to  the  students  generally 
insisted  upon  elsewhere  and  vsdth  the  advantage  of  a  more  or  less  extended 
international  circulation  among  experts,  everything  can  be  speedily 
brought  to  the  knowledge  of  those  most  interested  and  competent.  To 
know  that  results  will  thus  appear  without  delay  is  itself  a  real  stimulus, 
and  it  is  fortunate  that  evaluation  of  such  work  is  coming  to  be  a  more 
and  more  prominent  factor  in  determining  appointments  to  univei'sity 
positions.     The  quality  of  mind  which  makes  success  here  is  infinitely 


Philosophy.  183 

more  inspiring  to  students,  even  of  lower  grades,  than  the  rehearsal  of 
second-hand  knowledge  perhaps  many  removes  from  its  source.  Very- 
much  might  be  said  upon  the  effect  of  research  as  a  stimulant  to  the 
teacher,  while,  from  still  another  point  of  view,  the  fact  that  the  instruc- 
tor has  entered  the  great  arena  and  submitted  his  productions  to  the 
critical  estimate  of  experts,  gives  his  pupils  confidence  in  him  as  an 
authority  and  not  a  mere  echo.  The  provision  of  a  sufficient  number 
of  reprints  for  circulation  among  special  journals  that  will  notice  each 
work,  and  for  exchange  with  other  productive  workers  or  departments,  is 
another  one  of  the  new  university  problems  unknown  to  the  college,  to 
the  fuller  exploitation  of  which  the  new  journal  here  contemplated  and 
elsewhere  spoken  of  will  be  devoted. 

Great  importance  has  always  been  attached  here  to  the  methods  of 
bringing  students  into  immediate  and  personal  contact  with  the  latest 
literature,  especially  upon  the  topics  of  their  theses  or  those  related  to  the 
original  researches  upon  which  they  may  be  engaged.  The  exchanges  of 
the  journals  constitute  a  carefully  selected  list  of  nearly  three  score  peri- 
odicals, all  of  which,  besides  those  regularly  subscribed  for  by  the  library, 
are  immediately  available.  Besides  these  the  journals  receive  a  large 
number  of  the  most  important  books  and  pamphlets  within  their  field, 
especially  from  American,  English,  French,  and  German  houses.  These 
works  together  with  the  smaller  resources  of  my  own  library,  which 
mainly  supplements  that  of  the  University,  are  at  the  disposal  of  students, 
who  are  often  encouraged  to  write  brief  book  notices  for  publication. 
The  frequent  personal  conferences  with  each  student  in  the  department 
keeps  the  instructor's  mind  alert  to  find  out  and  bring  to  the  immediate 
notice  of  each  anything  bearing  upon  his  theme.  Meetings  are  occasion- 
ally held  in  my  library,  where  I  spend  the  evening  going  through  my 
shelves,  taking  out  the  books  that  I  deem  most  important  and  that  have 
helped  me  most,  briefly  characterizing  each,  and  passing  it  around  for 
actual  inspection.  If  I  had  at  my  disposal  an  hour's  time  of  a  dozen  of  the 
most  eminent  men  to  utilize  in  such  a  way  as  would  be  of  greatest  benefit  to 
me,  I  think  I  should  ask  them  to  do  precisely  this,  for  they  would  thus  be 
giving  me  to  some  extent  a  key  to  their  own  intellectual  activity  and 
direction.  Where  this  method  is  extended  to  monographs  and  pamphlet 
publications,  the  collection  of  which  our  system  of  exchanging  theses 
promises  to  greatly  enrich,  its  value  is  still  greater  for  special  students. 


184  PMlosoijhy. 

Genetic  psychology,  which  one  sub-department  of  this  University  so 
conspicuously  represents,  is  far  larger  than  the  child-study  of  mothers' 
clubs  or  teachers'  associations.  It  is  simply  the  entrance  of  Darwinism 
into  the  field  of  mind.  Underneath  it  lies  the  great  transforming  concep- 
tion that  the  soul  is  as  complex,  as  old,  and  as  gradually  unfolded  as  the 
body,  and  like  it  must  be  studied  comparatively  in  view  of  all  that  the 
psychic  life  of  the  lower  or  even  the  lowest  organisms  can  teach  us. 
The  new  methods  cross-section  the  old  classification  methods  which  make 
memory,  will,  perception,  imagination,  etc.,  so  many  faculties,  and  seek  to 
trace  the  origins  of  the  higher  mental  powers  to  their  faintest  beginnings 
near  the  dawn  of  animal  life.  The  most  fundamental  activities  are  those 
whose  roots  extend  lowest  down  in  the  scale  of  existence,  and  these  are 
also  they  that  send  their  tops  highest.  The  conception  that  mind,  as  we 
know  it  in  consciousness,  has  been  developed  out  of  something  very  differ- 
ent that,  like  organic  forms,  tends  to  vary  and  change  indefinitely  is  a 
new  conception  and  is  sure  eventually  to  reconstruct  out  of  new  and  old 
elements  a  far  larger  and  more  adequate  city  of  Man-soul  with  reformed 
administrative,  educational,  religious,  and  other  functions.  This  move- 
ment appears  in  biology  in  the  tendency  to  study  psychic  phenomena  in 
the  most  rudimentary  and  microcosmic  organisms.  It  appears  again  in 
the  new  and  careful  studies  of  instinct  in  the  higher  animals,  where  con- 
ditions can  be  varied  and  educational  experiments  conducted  with  great 
precaution  and  detail.  Another  root  of  the  genetic  movement  is  in  the 
anthropology  of  myth,  custom  and  belief  among  primitive  and  savage 
peoples  ;  another  in  the  studies  of  degenerative  types  among  the  defective 
classes,  where  decay  has  inverted  the  evolutionary  order. 

It  is  on  this  foundation  that  the  child-study  movement  rests,  and  its 
amazing  development  cannot  be  adequately  explained  without  a  due  ap- 
preciation of  this  wider  field.  The  minute  observation  and  annotation, 
the  measuring  and  weighing  of  a  single  child,  or  the  collective  study  of 
one  topic  upon  the  basis  of  returns  from  very  large  numbers  of  children 
with  the  help  of  questionnaires,  anthropometric  work  with  its  carefully 
wrought  out  averages,  —  all  this  appeals  to  the  instinctive  love  of  children; 
out  of  it  has  grown  the  new  conception  of  childhood  as  the  most  generic 
period  of  life,  wherein  the  limitations  of  individuality  are  not  yet  so  pain- 
full}^ apparent  as  in  adults,  and  it  has  given  us  new  conceptions  concern- 
ing the  nature  of  genius,  the  laws  of  growth,  the  origin  of  fear,  anger, 
love,  the  conditions  of  health,  the  nascent  periods  of  maximal  interest  in 


Philosophy.  185 

special  lines  and  topics,  until  at  last  education  seems  likely  to  have  under 
it  a  far  more  solid  and  scientific  foundation  than  it  has  ever  yet  attained. 
While  this  subject  has  as  yet  occupied  but  a  slight  and  recent  portion  of 
our  curriculum,  so  much  has  already  been  accomplished  as  to  warrant  the 
very  fairest  hopes  for  the  future.  Among  the  first  results  likely  to  be 
witnessed  are  the  gradual  transformation  of  the  methods  of  teaching  and 
of  investigating  the  problems  of  the  special  philosophical  disciplines  some- 
what analogous  to  the  transformation  of  anatomy  and  morphology  under 
the  influence  of  embryology.  How  far  this  movement  will  extend  among 
the  other  university  studies,  and  whether  with  or  without  any  new  coor- 
dination of  the  successive  stages  of  individual  growth  with  the  historic 
development  of  different  philosophical  systems  as  first  presented  by  Hegel, 
it  is  impossible  to  foretell. 


THE   LIBEAEY. 

By  Louis  N.  Wilson,  Librarian. 

Fkom  the  foundation  of  the  University  the  library  has  been  consid- 
ered an  important  factor  and  has  received  a  great  deal  of  attention 
from  the  Founder,  President,  and  Faculty.  Immediately  upon  his  ap- 
pointment, the  President  requested  each  member  of  the  University  to 
draw  up  a  list  of  books  in  his  special  field,  laying  particular  stress  upon 
important  serials  and  special  monographs.  These  lists  were  carefully 
collated,  duplicates  weeded  out,  and  arranged  in  order  for  purchase. 
The  total  number  of  items  amounted  in  June,  1889,  to  upward  of  fifteen 
thousand,  a  very  large  proportion  being  books  and  journals  in  foreign 
languages.  In  order  to  secure  for  the  University  the  best  possible  rates, 
lists  of  standard  works,  both  in  sets  and  single  volumes,  were  submitted 
for  competition  to  a  number  of  well-known  booksellers  both  in  this 
country  and  in  Europe.  This  necessitated  some  delay,  but  it  was  fully 
warranted  by  the  resultant  saving  in  cost. 

To  illustrate  this  point,  the  figures  submitted  by  five  firms  for  an 
identical  list  of  742  items  are  given  here,  viz.:  $1806.30,  $1810.90, 
$1971.86,  $2038.89,  $2166.41,  showing  a  maximum  difference  of  $360.11. 

After  carefully  comparing  all  the  lists  sent  in,  and  taking  into  con- 
sideration the  condition  of  the  books  offered,  orders  were  placed  with 
firms  in  New  York,  Boston,  London,  Paris,  Berlin,  Leipzig,  and  Vienna. 

During  the  past  few  years,  owing  to  our  very  peculiar  and  constantly 
changing  customs  and  postal  regulations,  it  has  become  more  and  more 
desirable  to  import  from  Europe  through  some  responsible  bookseller  in 
this  country,  in  order  to  avoid  the  frequent  and  often  vexatious  annoy- 
ances consequent  upon  individual  importations.  Having  decided  upon 
a  particular  bookseller,  orders  were  freely  placed  with  the  understanding 
that  the  library  should  receive  the  lowest  possible  rates  consistent  with 
good  service,  and  from  time  to  time  lists  were  sent  to  other  firms  in  order 
to  be  assured  that  the  agreement  was  faithfully  carried  out.     A  recent 

187 


188  The  Library. 

test  of  this  kind  showed  the  following  quotations  for  thirty-five  volumes, 
1105.26,  $107.57,  1120.00.  In  general,  the  plan  has  worked  exceedingly 
well. 

During  the  summer  of  1889,  while  these  orders  were  being  executed, 
Mr.  Clark  placed  the  first  books  in  the  library  by  donating  about  thirty- 
two  hundred  volumes.  A  large  proportion  of  these,  on  history,  biogra- 
phy and  travel,  were  given  with  the  original  bookcases  as  they  had 
stood  in  his  own  private  library.  Another  part  of  the  collection  con- 
sisted of  the  following  sets  of  bound  periodicals,  almost  all  complete 
down  to  the  end  of  1883  :  Atlantic  Monthly^  Blackwood'' s  Magazine^  Cen- 
tury Magazine,  Cornliill  Magazine,  Edi7ihurgh  Bevieiv,  Fortiiiglitly  Review, 
Cientlemaii's  Magazine,  Harper  s  Magazine,  JjittelVs  Living  Age,  Macmillan''s 
Magazine,  North  American  Revieiv,  North  British  Review,  Notes  and 
Queries,  Popular  Science  Monthly,  Putnam's  Magazine,  Quarterly  Review, 
and  Scribner's  Monthly,  also  a  set  of  the  Report  on  the  Scientific  Results 
of  the  Voyage  of  H.  M.  S.  Challenger,  during  the  years  1872-76.  Yet  a 
third  part  consisted  of  a  large  number  of  rare  old  books,  some  of  which 
are  fine  examples  of  early  printing  when  there  was  no  title-page,  no 
pagination,  date,  or  printer's  name,  and  where  the  initial  letters  were 
omitted  to  be  inserted  later  by  hand.  Of  these  fine  old  volumes,  the 
following  are  mentioned  as  examples :  — 

Paulus  de  Sancta  Maria  Scrutinium  scripturarum.     Probably  the  oldest  book 

in   cm-  library,   with   no   title-page,   colophon,   pagination,    or   signatures. 

Eubricated  throughout. 
Rationale  divinorura  officiorum.     Supposed  to  have  been  printed  at  Basle  in 

1474-75. 
Astexanis  Suma.  Libri  VIII.,  de  preceptis,  de  virtutibus  et  viciis;  de  sacra- 

mentis  de  sacro  penitentie,  de  sacramento  ordinis,  de  excommunicatione ;  de 

matrimonio.     Venetiis,  1478. 
Robert!   Caraczoli   de   Licio   de    timore   divinorum    judiciorum   ac   de   morte. 

Nuremberge,  1479. 
Albert!  de  Padua  expositio  Evangeliorum  dominicalium  totius  anni  et  concor- 

dancia  quatuor  evangelistarum  in  passionem  dominicam  a  Nicolao  Vinekel- 

spickel.     Ulm,  1480. 
Sancti  Thome  de  Aquino  ordinis  predicatorum  super  quarto  libro  sententiarum 

preclarum  opus.     Venetiis,  1481. 
Liber  moralitatum  elegantissimus  magnarum  rerum  naturalium  lumen  anime 

dictus.     1482. 
Sancti  Hieronimi  Vitse  Patrum  Sanctorum  Egiptiorum.     Ntirnberg  (Koburger) 

1483. 


The  Library.  189 

Blondi    Flavii    historiarum    ab   inclinatione    Eomanorum    Imperii,    libri    XI. 

Venetiis  per  Octavianum  Scotum.     1483. 
Johannis  de  Turrecremata  questionum  dignissimarum  cum  solutionibus  earum- 
den,  etc.     Davantrise,  1484.     A  work  of  the  celebrated  Spanish  Dominican 
Juan  de  Torquemada. 
Legende  de  sancti  composte  per  Jacobo  de  Voragine.     Venetia,  1484. 
An  old  German  almanac  beautifully  printed  in  red  and  black  and  pasted  on 
one  of  the  covers  of  Hieronimi  Vitm  Fatrum.     It  runs  from  1486  to  1579, 
and  was  probably  printed  at  the  earlier  date. 
Summa  Eainerij  de  Pisis.     Venetiis,  1486. 

Liber  Cronicarum  cum  figuris  et  imaginibus  ab  initio  mundi  usque  nunc  tem- 
poris  Impressum  ac  finitum  in  vigilia  purificationis  Marie  in  imperiali 
urbe  Augusta  a  Johanne  Schensperger.  Anno  ab  incarnatione  domini  1497. 
The  so-called  Nuremberg  Chronicle,  with  numerous  woodcuts  by  Wolge- 
muth,  the  master  of  Albrecht  Dlirer. 
Sermones  Pomerii  de  Tempore  Hyemales  et  Estivales  et  sermones  quadragesi- 
males  per  Helbartum  de  Themeswar.  Hagenaw,  1502,  With  rubricated 
initials. 
Pauli  Jovii  elogia  virorum  bellica  virtute  illustrium  veris  imaginibus  supposita, 

quae  apud  Musseum  spectantur,     Florentiae,  1551. 
Ramusio,  Primo  volume,  &  Terza  edizione  delle  navigationi  et  viaggi.     Vene- 
tia,  Giunti,  1563.     The  first  volume  of  Ramusio's  well-known  collection  of 
voyages  and  travels,  containing  among  other  things  Pigafetta's  log  during 
the  first  voyage  around  the  world  under  Magalhaes. 
Missale  Romanum,  ex  Decreto  Sacrosancti  Concilii  Tridentini  restitutum,  Pii  V. 

Pont.  Max.  jussu  editum.     Venetiis,  apud  Juntas,  1602. 
The  Bible :  that  is  the  Holy  Scriptures  contained  in  the  Old  and  New  Testa- 
ment.    London,  1610.     A  copy  of  the  so-called  Breeches  Bible. 
Missale  Romanum,  ex  Decreto  Sacrosancti  concilii  Tridentini  restitutum,  Pii  V. 
Pont.  Max.  jussu  editum  et  Clementis  VIII.  auctoritate  recognitum.     Ingol. 
stadii,  1610. 
Montanus  (Arnoldus)  De  Nieuwe  en  Onbekende  Weereld  of  Beschryving  van 

America.     Amsterdam,  1671.     An  old  description  of  America  in  Dutch. 
Esquemeling  (John)  and  Ringrose  (Basil),  History  of  the  Bucaniers  of  America. 
London,  1695.     Esquemeling,  who  spent  many  years  at  Tortuga,  gives  here 
a  very  graphic  account  of  the  buccaneers. 
Armenian  Bible.     Venice,  1805.     Fleeing  from  the  persecution  of  their  ortho- 
dox brethren,  the  Catholic  Armenians  of  the  mechitaristic  order  established 
themselves  at  the  island  of  San  Lazzaro,  granted  them  by  the  Republic  of 
Venice.     Many  a  learned  volume  issued  from  their  press,  of  which  this  is 
a  specimen. 
New  Testament  in  Lettish  language.     Mitau,  1816. 

Select  Fables ;  with  cuts,  designed  and  engraved  by  Thomas  and  John  Bewick, 
previous  to  the  year  1784 ;  together  with  a  Memoir  and  a  descriptive  cata^ 


190  The  Library. 

logue  of  the  works  of  Messrs.  Bewick.     Newcastle,  1820.     Thomas  Bewick 
is  considered  the  restorer  of  wood  engraving  in  England. 
Cookson   (Mrs.  James).     Flowers  drawn  and  painted  after  nature  in  India. 
1834. 

In  addition  to  a  number  of  books  presented  to  the  library  by  Presi- 
dent Hall,  we  are  indebted  for  gifts  to  the  following  citizens  of  Worces- 
ter :  Hon.  George  F.  Hoar,  Mr.  Henry  J.  Howland,  Hon.  Henry  L. 
Parker,  Mr.  Samuel  H.  Putnam,^  the  late  Hon.  W.  W.  Rice,  Hon. 
Stephen  Salisbury,  Hon.  John  D.  Washburn,  and  Hon.  John  E.  Russell 
of  Leicester. 

To  receive  the  books  temporary  wooden  stacks  were  erected  in  the 
main  library  room,  and  so  substantially  were  they  constructed  that  they 
are  still  serviceable.  Solid  oak  shelving  was  put  up  on  both  sides  of  the 
reading-room,  adjoining  the  main  library  room,  with  a  three-foot  pro- 
jecting shelf  three  and  a  half  feet  from  the  floor,  upon  which  the  current 
numbers  of  periodicals  are  displayed. 

To  the  problem  of  cataloguing  and  classification,  always  a  difficult  one, 
both  the  President  and  the  members  of  the  Faculty  gave  a  good  deal  of 
time  and  attention.  It  was  felt  that  the  scheme  of  classification  must  not 
be  too  rigid,  and  that  nothing  should  be  allowed  to  interfere  with  the  free 
use  of  the  books  by  all  members  of  the  University.  The  books  were  first 
carefully  classified  upon  the  shelves  by  departments,  and  marked  as 
follows  :  — 

A.  Works  of  General  Eeference.  I.  Psychology. 

B.  Journals.  J.  Philosophy. 

C.  Mathematics.  K.  Ethics. 

D.  Physics.  L.  Criminology. 

E.  Chemistry.  M.  Anthropology. 

F.  Zoology.  M".  Education. 

G.  Physiology.  0.  Botany. 
H.  Pathology. 

The  various  subdivisions  in  each  department  may  be  inferred  from 
that  of  the  mathematical  department. 

lA  copy  of  '■'■Justini  historici  clarissimi  in  Trogi  Pompeii  historias  Lihri  XLIIIiy 
Venice,  Jenson.  I4.70.  Dukede  Noailles'  copy  of  the  editio  princeps.  "  Viroruni  Illustrium 
vita:  ex  Plutarcho  Groeco in Latinum  Versce  Solertiqae,  cura  emendatce  fceliciter  expUciut :  ""per 
Nicolaum  Jensen  Gallicum  Venetiis  Ipressoe.  1478,  die.  II  Januarii.  2  vols.  "The 
Scientific  Papers  of  James  Clerk  Maxwell."  Edited  by  W.  D.  Niven,  F.  R.  S.  The  Univer- 
sity Press,  Cambridge,  1890.    2  vols. 


The  Library, 


191 


C.  —  Mathematics. 

In  Mathematics,  C,  the  books  are  grouped  in  ten  divisions,  designated 
by  the  numerals  1,  2,  3,  4,  5,  6,  7,  8,  9,  0,  immediately  following  the  let- 
ter C  ;  every  division  is  subdivided  into  sections  of  which  each  is  desig- 
nated by  a  second  numeral  following  that  indicating  the  division.  The 
cipher,  0,  always  denotes  a  miscellaneous  division  or  section.  The  math- 
ematical works  are  arranged  on  the  shelves  in  accordance  with  the  fol- 
lowing classification,  the  subdivisions  of  which,  however,  are  not  all  used 
at  present.  The  italicized  part  of  each  title  is  that  printed  on  the  sliding 
shelf  label. 


C  1.   History  and  Philosophy. 
CI.  1.   Bibliography. 
CI.  2.    History. 
C  1.  3.    Biography. 
C  1.  4.    Philosophy. 

C  2.   Collections. 

C  2.  1.    Works,  complete  and  select. 
C  2.  2.    Compendia,  Dictionaries. 
C  2.  3.    Tables.     Formulai. 

C  3.   Symbolism  and  Operation. 
C  3.  1.   Symbolic  Methods. 
C  3.  2.    Operations. 
C  3.  3.   Multiple  Algebra  (ref.  C  9). 
C  3.  4.    Symbolic  Logic. 
C  3.  0.   Miscellaneous  Symbols. 

C  4.   Arithmetic. 

C  4.  1.   Elementary  Arithmetic. 

C  4,  2.    Coyitinued  Fractions. 

C  4.  3.    Numerical  Series. 

C  4.  4.  Finite  Differences  and  Sum- 
mation. 

C  4.  5.  Permutations  and  Combinor 
tions. 

C  4.  6.    Probabilities. 

C  4,  7.    Theory  of  Numbers. 

C  5.    Algebra.     (Per   Multiple   Alge- 
bra see  C  3.  3.) 
C  5.  1.    Elementary  Algebra. 
C  5.  2.    Determinants. 


C  5.  3.  TJieory  of  Equations. 

C  5.  4.  Simidtaneous  Equations. 

C  5.  5.  Transformation. 

C  5,  6.  Invariants. 

C  6.   Infinitesimal  Calculus. 


C6. 

1. 

Limits  and  Infinite  Series. 

C6. 

2. 

Functions  of  a  Real  Varia- 
ble. 

C6. 

3. 

Differential  Calculus. 

C6. 

4. 

Integral  Calculus. 

C6. 

5. 

Total  i)i^erential  Equations. 

C6. 

6. 

Partial  Di^erential  Equa- 
tions. 

C6. 

7. 

Functions  Derived  from 
Differential  Equations. 
Sp^herical  Harmonics. 

C6. 

8. 

Calcidus  of  Variations. 

C  7.   Theory  of  Functions. 

C7. 

1. 

General  Tlieory. 

C7. 

2. 

Algebraic  Functions. 

C7. 

3. 

Exponential  and  Trigono- 
metric Functions. 

C7. 

4. 

Elliptic  Functions  and  In- 
tegrals. 

C7. 

5. 

Hyperelliptic  and  Abelian 
Functions  and  Integrals. 

C7. 

6. 

Various  Functions  (fuch- 
siennes,  etc.). 

C7. 

7. 

Functions  of  Several  Varia- 
bles. 

192 


The  Library. 


C  8.    Geometry. 

C  8.  1.  Elementary  Geometry  and 
Trigonometry. 

C  8.  2.   Analysis  Situs. 

C  8.  3.  Analytic  Geometry  in  Gen- 
eral. 

C  8.  4.  Projective  Geometry.  Mod- 
ern Synthetic  Geometry. 

C  8.  5.  Special  Systems  of  Geomet- 
ric Analysis. 

C  8.  6.   Plane  Loci  in  particular. 

C  8.  7.  Loci  in  8  Dimensions  in  par- 
ticular. 

C  8.  8.  Hyperspace  and  NonrEucli- 
dean  Geometry. 

C  8.  9.   Applications  of  Geometry. 


C  9.   Extensive  Algebra  (ref.  C  3.  3). 

C  9.  1.  Geometric  Representation  of 
the  Lnaginary. 

C  9.  2.    Quaternions. 

C  9.  3.  Geometric  Algebras  (Clif- 
ford). 

C  9.  4.  Ausdehnungslehre  (Grass- 
mann). 

C  9.  5.   Equipollences  (Bellavitis). 

CO.  Miscellaneous. 
C  0.  1.  Apparatus. 
C  0.  2.   Recreations,  Games,  Puzzles, 

etc. 
C  0.  9.   Paradoxes  and  Paradoxers. 
Circle-squaring,  etc. 


As  B  is  the  general  designation  of  periodicals,  each  periodical  exclu- 
sively devoted  to  one  department  is  designated  by  B,  followed  by  the 
letter  of  the  department  to  which  it  belongs,  thus : 

B  C.   Mathematical  Periodicals. 

B  A.  Miscellaneous  Periodicals.     Transactions  of  learned  societies,  etc. 

So  long  as  the  number  of  books  in  any  section  is  very  small,  they  are 
grouped  under  the  division  to  which  that  section  belongs,  and  are  desig- 
nated only  by  the  number  of  that  division.  All  books  which  refer  to 
several  divisions  are  placed  in  the  division  C  2  (collections),  and  all 
books  referring  to  several  sections  of  any  one  division  are  grouped  under 
that  division,  unless  they  refer  but  slightly  to  more  than  one  division  or 
section.  Volumes  of  a  set  are  not  separated,  but  the  whole  set  is  classed 
as  if  it  were  a  single  volume.  Otherwise,  every  book  is  placed  in  the 
narrowest  division  or  section  to  which  it  belongs. 

The  library  has  two  card  catalogues  :  — 

I.  An  author's  catalogue  arranged  alphabetically  with  miscellaneous 
and  anonymous  sections,  so  that  nearly  all  books  in  the  library  are 
represented  in  it. 

II.  A  subject  catalogue  which  is  at  the  same  time  a  shelf  and  an 
inventory  catalogue.  This  is  arranged  as  follows :  Every  volume  and 
every  pamphlet  has  its  card,  so  that  each  card  represents  a  volume. 
All  the  books  are  classified  and  arranged  upon  the  shelves  according  to 
the  departments,  divisions,  and  subdivisions,  but  under  each  subdivision 


The  Library.  193 

books  are  placed  alphabetically  by  authors.  While  each  case,  tier,  and 
shelf  is  permanently  labelled,  the  demarcation  between  the  subdivisions  is 
made  by  sliding  shelf  label  holders  bearing  the  subject,  division,  and  sub- 
division. These  label  holders  being  movable,  the  subdivisions  can  easily 
be  enlarged  as  new  books  are  added. 

In  mathematics,  for  instance,  C  1,  history  and  philosophy,  comes  first, 
with  the  first  subdivision,  CI,  1,  bibliography.  First  on  the  top  shelf, 
and  therefore  first  in  the  catalogue  drawer  set  apart  for  these  tiers, 
comes  bibliography,  beginning  with  authors  in  A,  and  so  on  through  the 
alphabet  to  the  end  of  the  subject.  Then  come  history,  biography,  etc., 
on  through  mathematics  and  the  other  departments,  the  order  of  cards 
being  identical  with  the  order  of  the  books  upon  the  shelves,  reading 
down  the  tiers  as  down  a  printed  page. 

In  the  drawers  the  book  cards  are  separated  by  red  cards  projecting 
on  the  right  above  the  others,  and  on  these  projections  the  tier  and  shelf 
divisions  are  marked ;  they  are  also  separated  by  blue  cards  projecting 
above  the  others  on  the  left-hand  side,  on  which  the  subjects  are  marked. 
Whenever  the  position  of  any  book  is  changed,  it  is  only  necessary  to 
make  a  corresponding  change  in  the  position  of  its  card.  The  shelf  posi- 
tion of  each  book  is  marked  in  pencil,  not  upon  these  cards,  but  upon 
each  card  in  the  author's  catalogue,  and  in  the  book  itself,  in  order  that  it 
may  be  readily  found  and  replaced. 

New  books,  after  being  entered  in  the  author's  catalogue,  are  kept  in  a 
case  reserved  for  them  for  a  few  weeks  before  being  permanently  placed 
on  the  shelves  and  entered  in  the  inventory  catalogue. 

A  full  list  of  all  serial  publications  taken  by  the  library  is  kept  in  a 
special  drawer  of  the  catalogue  case,  so  that  a  person  unfamiliar  with  the 
library  may  ascertain,  with  very  little  trouble,  what  periodical  publications 
are  to  be  found  here. 

Worcester  is  fortunate  in  possessing  an  excellent  Public  Library  of 
more  than  120,000  volumes,  and  well  supplied  with  serial  publications. 
In  the  early  years  of  the  University,  it  was  the  hope  of  the  Founder  that 
we  might  confine  our  purchases  to  such  books  and  journals  as  were  not  to 
be  found  in  the  Public  Library,  and  that  the  two  might  supplement  each 
other ;  this  plan  was  largely  carried  out  in  the  earlier  years,  but  later  the 
needs  of  our  students  demonstrated  the  necessity  of  the  duplication  of 
the  more  important  scientific  publications,  though  we  still  depend  upon 
the  Public  Library  for  works  of  a  less  special  character,  and  our  students 


194  The  Library. 

have  availed  themselves  of  the  library  privileges  thus  extended  to  them 
to  the  fullest  extent. 

Besides  its  indebtedness  to  the  Worcester  Public  Library  the  Uni- 
versity is  under  great  obligations  to  the  following  for  frequent  loans: 
Library  of  the  Surgeon-General's  Office,  Washington,  D.C.  ;  Library  of 
Harvard  University ;  The  City  Library  Association  of  Springfield,  Mass. ; 
Boston  Public  Library ;  Public  Library,  Cleveland,  Ohio ;  Trinity  College 
Library  and  Case  Memorial  Library,  of  Hartford,  Conn. ;  Library  of  Yale 
University  ;  Forbes  Library,  Northampton,  Mass. ;  Library  of  Vassar 
College ;  and  many  others.  Several  of  these  libraries  have  freely  lent  us 
books  and  volumes  of  serial  publications,  often  of  the  greatest  importance 
to  those  engaged  in  research  work.  No  library,  however  large,  can  hope 
or  expect  to  be  prepared  to  meet  all  the  calls  upon  it,  and  a  glance  at 
the  diverse  and  advanced  character  of  the  publications  issued  from  this 
University  i  shows  how  varied  and  numerous  are  the  demands  upon  this 
department. 

To  the  Library  of  the  American  Antiquarian  Society  we  are  especially 
indebted  for  the  kindly  spirit  of  cooperation  invariably  shown.  While 
strictly  a  reference  library,  its  officers  have  ever  been  ready  and  willing  to 
make  reasonable  exceptions  in  aid  of  the  cause  of  historical  and  scientific 
research. 

The  library  is  a  veritable  laboratory,  and  is  looked  upon  as  a  work- 
room, and  not  as  a  museum  with  contents  too  sacred  to  be  profaned  by 
use.  It  is  a  favorite  meeting-place  for  professors  and  students,  where 
the  heads  of  departments  meet  their  men  to  direct  their  reading  and 
demonstrate  to  them  how  to  make  the  best  use  of  a  well-selected  collection 
of  scientific  books.  The  books  are  readily  accessible  to  every  member  of 
the  University,  and  there  is  no  limit  to  the  number  that  may  be  taken 
out.  Each  one  enters  the  volumes  he  takes  out  upon  a  printed  form  pro- 
vided for  that  purpose  ;  if  not  returned  at  the  end  of  ten  days,  they  are 
renewed  by  the  librarian  for  another  period  of  ten  days,  at  which  time 
they  must  be  returned,  but  may  be  taken  out  again  upon  the  following  day. 

The  library  is  open  to  all  persons  outside  the  University  who  are 
interested  in  any  of  its  lines,  and  its  books  are  freely  lent  to  such  persons, 
who  are  thus  placed  for  the  time  being  upon  the  same  footing  as  mem- 
bers of  the  University ;  and,  while  we  borrow  during  term  time  an  aver- 
age of  fifty  volumes  a  month,  we  lend  as  freely.     The  library  is  rich  in 

1  See  Bibliography  at  the  end  of  this  volume. 


The  Library.  195 

certain  special  lines,  and  is  often  used  by  experts  from  other  universities, 
state  and  national  institutions. 

President  Hall  has  an  exceptionally  fine  private  library,  especially  rich 
in  pamphlets  and  special  monographs  in  the  various  fields  of  philosophy, 
psychology,  and  education.  During  these  ten  years  all  students  have 
been  permitted  to  draw  upon  it  as  freely  as  upon  the  University  library, 
and  the  efficiency  of  this  department  has  been  largely  due  to  Dr.  Hall's 
broad-minded  and  liberal  conception  of  the  function  of  the  printed  vol- 
ume. In  his  various  courses  he  frequently  gives  demonstrations  of  books, 
pointing  out  the  best  books  in  each  subject,  the  best  to  buy,  the  best  to 
read,  emphasizing  and  explaining  the  strong  points  in  each,  etc. 

In  spite  of  the  absolute  freedom  of  the  library,  the  loss  of  books  has 
been  surprisingly  small.  Once  a  year  the  books  are  carefully  checked  by 
means  of  the  shelf  cards,  and  in  very  few  years  have  the  losses  amounted 
to  more  than  two  or  three  volumes.  The  missing  volumes  one  year  fre- 
quently turn  up  later,  so  that  a  careful  estimate  recently  made  shows  the 
actual  money  value  of  the  books  lost  in  ten  years  to  be  less  than  fifty 
dollars. 


Almost  all  who  are  interested  in  libraries  have  ideals  as  to  the  future 
development  of  their  special  fields,  and  the  librarian  has  attempted,  in  the 
course  of  the  past  ten  years,  to  formulate  an  ideal  of  an  university  library. 
He  alone  is  responsible  for  his  views,  and  is  encouraged  to  state  them  here 
by  the  fact  that  the  President  and  Faculty  have  given  him  the  greatest 
freedom  and  their  warmest  support  in  all  matters  pertaining  to  his  de- 
partment. 

The  ideal  library  should  be  housed  in  its  own  building,  and  not  rele- 
gated to  rooms  in  a  building  constructed  for  other  purposes.  In  con- 
structing such  a  building,  the  chief  end  in  view  should  be  to  provide 
every  facility  for  the  use  of  books,  and  this  end  should  never  be  sacrificed 
for  architectural  features  or  artistic  purposes.  Each  department  in  the 
University  should  have  a  working  library  in  its  own  rooms,  but  whatever 
books  are  placed  in  these  department  libraries  should  be  duplicated  in  the 
main  library.  The  building  should  be  large  enough  to  allow  the  book 
shelves  to  be  arranged  around  the  rooms,  leaving  the  greatest  amount  of 
open  space  in  the  centre.     Movable  working  desks,  liberally  supplied  with 


196  The  Library. 

conveniences  for  writing,  and  containing  ample  drawer  space  for  note-books 
and  papers,  are  mucli  to  be  preferred  to  the  large  fixed  tables  usually 
found  in  library  buildings.  The  shelving  should  be  of  the  most  approved 
modern  type,  insuring  economy  of  space  and  the  proper  care  of  the  books, 
and  the  highest  shelf  within  easy  reach  from  the  floor.  The  rooms  should 
be  provided  with  every  possible  convenience,  including  a  sufficient  num- 
ber of  comfortable  chairs,  with  cozy  nooks  and  corners  inviting  to  a  quiet 
half-hour  with  a  book,  when  one  would  otherwise  be  disinclined  to  read. 
That  the  light  should  be  good,  the  ventilation  absolutely  perfect,  and  the 
attendants  have  but  one  purpose  —  the  service  of  the  readers  —  are  obvi- 
ous essentials. 

In  these  days  of  rapid  multiplication  of  new  libraries  and  enlargement 
of  many  older  ones,  there  is  a  great  demand  for  complete  sets  of  serial 
publications,  and  many  of  the  important  journals  are  growing  rapidly 
scarce  and  difficult  to  obtain.  It  is,  therefore,  particularly  desirable  in  an 
institution  of  tliis  character  to  procure,  as  soon  as  possible,  full  sets  of  all 
the  serial  publications  in  its  various  departments  and  on  all  allied  subjects, 
and  every  effort  should  be  made,  and  no  expense  spared,  to  procure  all  the 
scientific  contributions  by  specialists  in  the  work  represented  here,  or  in 
departments  likely  to  be  of  service  in  research  work. 

The  current  numbers  of  all  these  publications  should  be  placed  before 
the  members  of  the  University  promptly,  as  it  is  imperative  that  those 
engaged  in  original  investigation  be  advised  of  the  latest  literatiu"e  on  the 
subject,  or  of  the  work  others  are  doing  along  similar  lines. 

A  most  important  part  of  a  good  library  is  its  catalogue.  The  day 
has  gone  by  when  men  can  afford  to  spend  hours  in  hunting  among  a  mass 
of  books  to  ascertain  what  the  library  possesses  upon  a  given  subject,  or 
to  rely  upon  the  memory  of  the  librarian  and  attendants,  be  the}^  ever  so 
erudite.  While,  therefore,  the  aim  should  be  to  keep  in  printed  and  card 
form  a  list  of  all  the  books  and  articles  that  have  been  written  upon  a 
given  subject,  nothing  should  be  allowed  to  interfere  with  the  prompt 
cataloguing  under  subject  headings  of  everything  that  the  library  pos- 
sesses. Two  questions  always  arise  here,  first,  "  Where  can  I  find  a  list 
of  all  printed  matter  upon  my  subject  ?  "  and  secondly,  "  How  much  of 
that  printed  matter  is  to  be  found  in  this  library  ?  "  A  complete  card 
catalogue  can  be  so  arranged  as  to  answer  perfectly  these  two  questions. 

In  this,  as  in  every  well-regulated  library,  printed  forms  should  be 
provided  to  encourage  readers  to  make  suggestions  and  complaints  to  the 


The  Library.  197 

library  coramittee  ;  the  latter,  in  no  case,  to  pass  through  the  hands  of 
the  librarian. 

The  subject  of  binding  is  always  an  important  one,  and  we  feel  very 
keenly  the  need  of  united  action  on  the  part  of  all  the  libraries  of  the  city 
in  this  respect.  A  careful  inquiry  has  developed  the  fact  that  between 
$4000  and  $5000  is  expended  yearly  by  the  various  institutions  in  this 
city  for  this  purpose.  There  are  unmistakable  signs  that  the  art  of  book- 
binding, which  has  for  ages  commanded  the  services  of  eminent  crafts- 
men, as  well  as  of  men  and  women  eminent  in  art,  is  receiving  increased 
attention  from  book  lovers  here,  and  the  time  may  not  be  far  distant  when 
this  question  will  be  taken  up  by  a  committee  representing  the  different 
libraries. 

There  would  seem  to  be  no  reason  also  why  the  various  institutions 
should  not,  in  the  near  future,  devise  a  system  of  cooperation,  as  is  already 
proposed  in  Toronto,  by  means  of  which  the  resources  of  all  the  libraries 
in  the  city  could  be  drawn  upon  by  each. 


KEPOET  OF  THE  TREASURER. 


At  the  first  meeting  of  the  Trustees  of  Clark  University,  May  4, 1887, 
Mr.  Clark  proposed  to  give  :  — 

(1)  "  The  sum  of  $300,000  (payable  as  the  same  shall  be  needed)  to  the  Gen- 

eral Working  or  Construction  Fund  to  be  applied  in  the  erection  of 
buildings  and  equipping  them  with  such  appliances  and  facilities  as 
may  be  deemed  necessary  for  putting  the  University  in  good  working 
order." 

(2)  "  The  sum  of  $100,000,  the  income  of  which  shall  be  devoted  to  the  support 

and  maintenance  of  a  University  Library." 

(3)  "  The  sum  of  $600,000,  the  income  of  which  is  to  be  devoted  to  the  general 

uses  of  the  University  in  its  support  and  management,  and  which 
for  the  sake  of  convenience  may  be  called  the  University  Endowment 
Fund." 
"The  Library  and  the  Endowment  Funds  are  never  to  be  diminished,  and 
no  part  of  the  principal  is  in  any  event  ever  to  be  applied  to  the  objects 
to  which  the  income  of  each  is  to  be  devoted.  If  by  any  accident  or 
loss,  either  of  said  funds  shall  at  any  time  become  impaired,  then  the 
income  of  each  of  said  funds  shall  be  added  to  the  principal  until  such 
impairment  is  made  good  and  the  funds  restored  to  their  original 
amounts." 

In  addition  to  the  foregoing  gifts,  Mr.  Clark  then  and  subsequently 
conveyed  to  the  Trustees  of  the  University,  real  estate,  the  valuation  of 
which  on  the  books  of  the  assessors  of  the  city  of  Worcester  is  ^135,600. 

In  the  Treasurer's  Annual  Statement  for  the  year  ending  August  31, 
1899,  which  follows,  is  an  account  of  the  Library  and  University  Endow- 
ment Funds. 

The  amounts  expended  for  construction  and  equipment  of  buildings 
under  the  terms  of  Mr.  Clark's  first  proposal  have  been  as  follows  :  — 

199 


200 


Report  of 


Construction  of  the  Main  University  Building         .         .  $159,780.60 

Construction  of  the  Chemical  Laboratory         .         .         .  56,131.94 

Equipment  of  the  Main  Building 18,480.28 

Equipment  of  the  Chemical  Laboratory  ....  14,801.47 

Apparatus  and  Supplies 29,082.73 

$278,277.02 
Additional  land  was   purchased  by  Mr.  Clark  for  the 

University  at  an  expense  of $12,233.04 

The  balance  to  make  up  the  proposed  $300,000        .         .  9,489.94 
was  subsequently  expended  in  the  additional  equip- 
ment of  the  different  departments. 


A  statement  of  the  expenses  of  the  several  departments  for  the  years 
1890-98,  inclusive,  including  the  amounts  expended  in  the  original  equip- 
ment above  mentioned,  is  appended. 


1890. 

1891. 

1892. 

1893. 

1894. 

Mathematics  .     .     . 

$  6,664.49 

S  7,235.00 

8  7,356.50 

8  6,926.40 

8  5,905.64 

Phvsics .     .     . 

17,214.20 

7,320.98 

6,768.46 

3,567.78 

2,330.30 

Chemistry .     . 

25,334.24 

7,491.00 

6,298.46 

2,693.26 

1,337.64 

Biologv .     .     . 

28,083.29 

15,429.70 

12,732.58 

3,676.47 

2,066.20 

Psvchology     . 

13,604.17 

11,400.00 

7,059.16 

7,666.03 

6,584.00 

Education .     . 

750.00 

1,550.00 

1,151.25 

1,586.13 

1,826.87 

Library .     .     • 

15,568.04 

5,733.41 

1,279.84 

1,334.45 

2,596.33 

Administration 

5,829.00 

2,900.00 

3,000.00 

3,800.00 

2,600.00 

Expense     .     . 

9,067.43 

5,162.92 

4,183.77 

8,983.01 

3,773.51 

Fellowships    . 

3,860.00 

4,560.00 

7,240.00 

5,280.00 

4,980.00 

8125,974.86 

§68,783.01 

§57,070.02 

845,513.53 

834,000.49 

Mathematics  . 

Physics    .     .  . 

Biology   .     .  . 

Psychology  .  . 

Education    .  . 

Library   .     .  . 
Administration 

Expense  .     .  . 
Fellowships 


1895. 


8  5,900.00 
2,329.07 
2,072.74 
6,015.46 
1,312.29 
1,628.72 
2,600.00 
3,434.13 
4,740.00 


830,032.41 


1896. 


5,900.00 
2,393.03 
2,200.00 
7,010.00 
1,2.50.00 
1,740.16 
2,600.00 
4,319.80 
4,620.00 


832.032.99 


1897. 


8  5,900.00 
2,948.73 
2,300.00 
7,010.00 
1,250.00 
2,456.00 
2,600.00 
4,237.82 
3,420.00 


832,122.55 


1898. 


8  5,900.00 
2,173.00 
2,054.24 
6,676.33 
1,250.00 
3,508.48 
2,600.00 
3,190.93 
1,500.00 


828,8.52.98 


the   Treasurer.  201 

In  addition  to  the  endowment  and  gifts,  which  have  already  been 
referred  to,  Mr.  Clark  has  given  to  the  University  for  its  general 
purposes :  — 

1889-90 $12,000 

1890-91 50,000 

1891-92 26,000 

1892-93 18,000 

$106,000 

The  University  has  received  from  Mrs.  Eliza  W.  Field  "a  fund  of 
$500  to  be  called  the  John  White  Field  Fund,  the  income  of  which  is  to 
provide  for  the  minor  needs  of  a  Scholar  or  Fellow." 

There  was  also  presented  to  the  Trustees  of  the  University  by  Hon. 
George  S.  Barton  of  Worcester  $5000,  the  income  of  which  is  to  be 
devoted  to  the  aid  of  "  some  one  or  more  worthy  native  born  citizens  of 
the  city  of  Worcester,  who  may  desire  to  avail  themselves  of  the  advan- 
tages of  the  institution." 

Hon.  Henry  L.  Parker,  in  the  summer  of  1892,  in  behalf  of  many 
citizens  of  Worcester,  presented  the  University  with  a  tower  clock  and 
the  sum  of  $781.30  to  provide  for  its  maintenance,  which  fund  is  known 
as  the  Clock  Fund. 


REPORT  OF  THE  TREASURER  TO  THE  TRUSTEES  FOR  THE  YEAR 
ENDING  AUGUST  31,  1899. 

To  THE  Trustees  of  Clark  University, 

Gentlemen,  —  I  have  the  honor  to  submit  herewith  my  annual  report 
for  the  year  ending  August  31,  1899. 

The  total   receipts  of  the  University  from  Sept.  1,  1898  to  Aug.  31,  1899, 

inclusive,  were         ....  $48,595.53 

The  total  disbursements  during  the  same  period  were      .         .         .       37,130.27 

Leaving  a  balance  on  hand  Sept.  1,  1899,  of $11,465.26 


202 


Report  of 


(A.) 

The  items  of  income  are  as  follows  :  — 

Gross  Income  of  the  University  Endowment  Fund . 
Gross  Income  of  the  Library  Fund  .         .         .         .         . 
Gross  Income  of  the  University        .         .         .         .         . 
Gross  Income  of  the  Summer  School,  1899 
Subscriptions  to  the  Fund  for  the  Decennial  Celebration 

From  the  Field  Fund 

Balance  from  previous  year 

Total 

(B.) 

The  expenditures  have  been  as  follows  :  — 

For  the  Department  of  Mathematics         .         .         .         . 

For  the  Department  of  Physics 

For  the  Department  of  Biology 

For  the  Department  of  Psychology 

For  the  Department  of  Education 

Administration         ........ 

Expense    .......... 

Field  Scholarship 

Expenses  of  Summer  School 

Expenses  of  the  Decennial  Celebration    .         .        .        . 

Library  Expenses     ........ 

Sinking  Fund   ......... 

Jonas  G.  Clark  on  account  of  premiums  .         .         .         . 

Accrued  interest  repaid 


(C.) 
The  incidental  earnings  of  the  University  from  fees,  etc.,  were 

(D.) 

Account  of  the  Summer  School  for  1899 :  — 

Receipts 

Expenses 

Balance  carried  to  University  Account 

(E.) 

Subscriptions  to  the  Decennial  Celebration  :  — 

Receipts 

Expenses  ........... 

Balance  on  hand  appropriated  to  the  publication  of  this  volume 


$28,407.33 
5,258.46 
1,586.00 
1,388.50 
4,150.00 
20.00 
7,785.24 

$48,595.53 


$  6,300.00 

2,641.11 

2,012.25 

7,966.82 

1,250.00 

2,700.00 

4,729.87 

20.00 

889.85 

3,156.85 

3,474.08 

700.00 

900.00 

389.44 

$37,130.27 

$  1,586.00 


$  1,388.50 

889.85 

$     498.65 


$  4,150.00 

3,156.85 

$      993.15 


the   Treasurer. 


203 


(F.) 
The  University  Endowment  Fund  is  invested  as  follows 

Book  value. 


Oregon  Kailway  and  Navigation  Co.,  4s    . 
West  Shore  R.  R.  Co.,  1st  Mtg.,  4s,  2361  . 
City  of  Cambridge,  Sewer  Loan,  6s,  1905  . 
Norwich  and  Worcester  R.  R.  Co.,  4s,  1927 
Rutland  R.  R.,  1st  Mtg.,  6s,  1902      . 
Wilkesbarre  and  Eastern  R.  R.,  1st  Mtg.,  5s 

1942 

Hereford  Ry.  Co.,  4s,  1930 

Chicago  and  Eastern  Illinois  R.  R.,  1st  Consol 

Mtg.,  6s,  1934  .... 

1st  Mtg.  Sink.  F.,  6s,  1907  . 
Wayne  Co.,  Michigan,  4s  . 
Northern  Ohio  Ry.  Co.,  1st  Mtg.,  5s 
Lowell,  Lawrence,  and  Haverhill  St.  Ry.,  1st 

Mtg.,  5s 

Worcester  and  Suburban  St.  Ry.,  1st  Mtg.,  5s 
Worcester  and  Marlboro  St.  Ry.,  1st  Mtg.,  5s 
Atchison,  Topeka  and  Santa  Fe  Ry.  Co.,  . 
Gen.  Mtg.,  4s       .         .         .         $18,500.00 
Adj.,  4s        ....  10,000.00 

Certif.  Gen.  Mtg.,  4s    .         .  250.00 

Second  Ave.  R.  R.  Co.,  New  York,  1st  Consol 

Mtg.,  5s,  1948  .... 

15  shares  Worcester  National  Bank 
71  shares  Norwich  and  Worcester  R.  R.    . 
Deposit  in  Worcester  Co.  Inst,  for  Savings 
Deposit  in  Five  Cents  Savings  Bank 
100  shares  Fitchburg  (preferred) 
35  shares  New  York,  New  Haven,  and  Hart 

ford  R.  R 

100  shares  Worcester  Traction  Co.  (preferred) 
New  England  Yarn  Co.,  5s        .        .        . 
Lake  Shore  Collaterals,  3|-s 
Invested  in  premiums        .... 
Cash  in  Worcester  National  Bank     . 


$110,000.00 
75,000.00 
20,000.00 
75,000.00 
25,000.00 

9,800.00 
9,350.00 

10.000.00 
1,000.00 

30,000.00 
3,000.00 

15,000.00 

6,000.00 

10,000.00 

25,000.00 


25,000.00 
2,250.00 

14,603.50 
5,000.00 

10,000.00 

10,300.00 

6,982.50 
10,700.00 
11,000.00 
50,000.00 
15,230.00 
28,920.25 

$614,136.25 


Market  value. 
Sept.  1,  1899. 

$112,750.00 
84,750.00 
22,600.00 
84,000.00 
26,500.00 

10,600.00 
10,000.00 

13,700.00 
1,145.00 

31,200.00 
3,180.00 

15,750.00 

6,240.00 

10,400.00 

18,500.00 

8,800.00 

250.00 

30,000.00 
2,700.00 

15,620.00 
5,000.00 

10,000.00 

11,800.00 

7,630.00 
10,450.00 
11,495.00 
50,000.00 

28,920.25 
$634,480.25 


204 


Report  of 


The  gross  income  of  the  University  Endowment 
Fund  was 


$28,407.33 


There  was  paid  from  this  :  — 

To  Sinking  Fund  to  provide  for  premiums  . 
To  Jonas  G.  Clark  on  account  of  premiums 
Accrued  interest  repaid       .... 


$700.00 
900.00 
389.44 


Leaving  net  income  carried  to  University  Account 

(G.) 
The  Library  Fund  is  invested  as  follows  :  — 


50  shares  Washington  National  Bank,  Boston 

25  shares  Tremont  National  Bank,  Boston  . 

50  shares  Merchants'  National  Bank,  Boston 

50  shares  National  Bank  of  Republic,  Boston 

50  shares  Union  National  Bank,  Boston 

50  shares  Second  National  Bank,  Boston     . 

50  shares  New  England  National  Bank,  Boston 

50  shares  Atlas  National  Bank,  Boston. 

61  shares  State  National  Bank,  Boston 

15  shares  Suffolk  National  Bank,  Boston    . 

50  shares  Eliot  National  Bank,  Boston 

50  shares  National  Bank  of  Commerce,  Boston 

50  shares  Boylston  National  Bank,  Boston 

43  shares  Old  Boston  National  Bank,  Boston 

10  shares  City  National  Bank,  Worcester  . 

15  shares  Norwich  and  Worcester  R.  R.  stock 

Northern  Ohio  R.  R.  Bonds,  5s  . 

15  shares  New  York,  New  Haven,  and  Hartford 

R.  R 

Invested  in  premiums  .... 

Deposit  in  Worcester  National  Bank  . 


The  gross  income  of  the  Library  Fund  was 

From  dividends  and  interest 

Rebate  on  bank  tax,     ...... 

Balance  carried  to  Library  Expense  Account 


$1,989.44 
$26,417.89 


Book  value. 

Market  value. 

Sept.  1,  1899. 

$  5,527.00 

$      6,000.00 

1,766.00 

(in  liquidation) 

7,934.60 

8,600.00 

7,994.88 

8,750.00 

6,829.50 

7,150.00 

9,162.50 

8,850.00 

8,237.50 

7,825.00 

6,293.50 

5,750.00 

6,938.01 

7,167.50 

1,527.21 

1,650.00 

6,598.00 

7,150.00 

5,552.62 

5,625.00 

6,530.75 

5,850.00 

4,527.63 

5,074.00 

1,500.00 

1,500.00 

3,000.00 

3,300.00 

4,000.00 

4,240.00 

2,992.50 

3,270.00 

150.00 

2,273.05 

2,273.05 

$99,335.25 

$100,024.55 

$4,085.77 

1,172.67 

5,258.44 


the  Treasurer,  205 

(H.) 

The  Library  Expense  Account :  — 

Unexpended  balance  from  previous  years    .        .        .      $3,091.18 

Credits  for  books  sold 412.38 

Income  of  the  Library  Fund  for  1899  .         .        .        .        5,258.46       $8,762.02 

Tbe  expenses,  including  $900  for  administration,  heat 

and  light,  were 3,886.46 

Leaving  a  balance  Sept.  1, 1899,  of       .        .        .  $4,875.56 

The  George  S.  Barton  Fund,  deposited  in  the  Worces- 
ter Co.  Inst,  for  Savings,  amounts  to    .                .  $7,239.24 
Income  during  the  year 278.43 

(J.) 

The  John  White  Field  Fund,  deposited  in  the  Worces- 
ter Co.  Inst,  for  Savings,  amounts  to    .         .         .  $653.22 
Income  during  the  year 25.74 

(K.) 

The  Clock  Fund,  deposited  in  the  Five  Cents  Savings 

Bank,  amounts  to $878.40 

Income  during  the  year 33.93 

(L.) 

The  Sinking  Fund,  to  provide  for  premiums,  is  de- 
posited in  the  Worcester  Five  Cents  Savings 
Bank,  and  amounts  to $2,670.42 

(M.) 
The  salaries  of  the  University  Faculty  were       .        .  $19,990.00 

(N.) 
Fellowships  and  Scholarships $1,310.00 

(0.) 
Salaries  of  employees $2,135.00 

(P.) 
Apparatus  and  supplies $870.18 

Respectfully  submitted, 

Thomas  H.  Gage,  Treasurer. 


206  Report  of  the  Treasurer, 

We  have  examined  the  books  and  accounts  and  securities  of  Clark 
University,  and  find  them  to  be  correct  and  as  stated  in  the  foregoing 
treasurer's  report  for  the  year  ending  August  31,  1899. 

James  P.  Hamilton, 
T.  H.  Gage,  Jr., 

Auditors. 


Id 


LECTUKES   ON   MATHEMATICS. 

By  Professor  Emile  Picard. 

Premiere  Conference. 

Sur  VExtension  de  quelques  Notions  Mathematiques,  et  en   particuUer  de 
VIdee  de  Fonction  depuis  un  Siecle. 

Mes  premiers  mots  seront  pour  adresser  mes  remerciments  au  Conseil 
de  cette  Universite  qui  m'a  fait  I'honneur  de  m'inviter  a  ces  fetes  et  m'a 
charge  de  prendre  la  parole  devant  quelques  mathematiciens  americains. 
C'est  un  honneur  auquel  je  suis  tres  sensible,  car  nous  savons  en  France 
que  les  etudes  mathematiques  se  developpent  rapidement  en  Amerique 
et  nous  suivons  ce  moavement  avec  une  tres  vive  sympathie.  Votre 
American  Journal  of  Mathematics  compte  parmi  les  journaux  periodiques 
les  plus  importants  et  renferme  de  remarquables  memoires,  et  je  lis 
toujours  pour  ma  part  avec  grand  profit  et  interet  le  Bulletin  de  la 
Societe  matbematique  americaine,  excellente  revue  historique  et  critique 
qui  tient  ses  lecteurs  au  courant  des  travaux  les  plus  recents.  J'ai 
appris  aussi  que  cette  Societe  allait  fonder  un  nouveau  recueil  destine 
a  des  memoires  plus  etendus  ;  je  ne  doute  pas  qu'il  ne  soit  appele  a  un 
brillant  avenir.  Dans  les  trois  causeries  que  nous  aliens  avoir  ensemble, 
je  ne  puis  songer  a  aborder  un  sujet  special  qui  demanderait  une  pre- 
paration particuliere.  Nous  allons  rester  dans  les  generalites  et  jeter  un 
rapide  coup  d'oeil  sur  I'extension  de  quelques  notions  mathematiques  et 
en  particulier,  de  I'idee  de  fonction  depuis  un  siecle. 

I. 

Toute  la  science  mathematique  repose  sur  I'idee  de  fonction  c'est  a 
dire  de  dependance  entre  deux  ou  plusieurs  grandeurs,  dont  I'etude  con- 
stitue  le  principal  objet  de  I'analyse.  II  a  fallu  longtemps  avant  qu'on 
se  rendit  compte  de  I'etendue  extraordinaire  de  cette  notion  ;  c'est  la 
d'ailleurs  une  circonstance  qui  a  ete  tres  heureuse  pour  les  progres  de  la 
Science.  Si  Newton  et  Leibnitz  avaient  pense  que  les  fonctions  continues 
n'ont  pas  necessairement  une  derivee,  ce  qui  est  le  cas  general,  le  calcul 

207 


208  Emile  Picard: 

differentiel  n'aurait  pas  pris  naissance  ;  de  meme  les  idees  inexactes  de 
Lagrange  sur  la  possibilite  des  developpements  en  series  de  Taylor  ont 
rendu  d'immenses  services.  Sans  vouloir  trop  generaliser,  on  pent  dire 
que  I'erreur  est  quelquefois  utile,  et  que,  dans  les  epoques  vraiment 
creatrices,  une  verite  incomplete  ou  approchee  pent  etre  plus  feconde  que 
la  meme  verite  accompagnee  des  restrictions  necessaires  ;  I'histoire  de  la 
science  confirme  plus  d'une  fois  cette  remarque  et,  pour  rappeler  encore 
Newton,  il  est  heureux  qu'il  ait  eu  au  debut  de  ses  recherches  pleine 
confiance  dans  les  lois  de  Kepler.  Les  geometres  du  siecle  dernier,  sans 
remonter  plus  haut,  ne  raffinaient  pas  sur  I'idee  de  fonction;  pour  eux, 
une  fonction  d'une  variable  est  une  fonction  qu'on  pent  representer  par 
une  courbe  formant  un  trait  continu ;  ce  sont  ces  fonctions  qu'Euler 
appelait  functiones  continuce.  La  question  de  la  representation  d'une 
fonction  arbitraire  sous  une  forme  analytique  dans  laquelle  interviennent 
seulement  les  operations  fondamentales  de  I'arithmetique  effectuees  un 
nombre  fini  ou  infini  de  fois,  se  posa,  semble-t-il  pour  la  premiere  fois 
a  propos  du  probleme  des  cordes  vibrantes.  D'Alembert  avait  donne 
I'integrale  de  I'equation 

sous  la  forme  f(x  +  at^  +  (f){x  —  at').  Daniel  Bernoulli  montra  qu'on 
pouvait  satisfaire  a  I'equation  differentielle  et  aux  conditions  aux  limites 
par  une  serie  trigonometrique,  et  il  affirma  que  cette  serie  donnait  la 
solution  la  plus  generale.  Ce  fut  I'occasion  d'une  longue  discussion  entre 
Bernoulli,  Euler  et  Lagrange.  Pour  ces  grands  geometres,  une  fonction 
arbitraire  etait  toujours  la  fonction  arbitraire  susceptible  d'etre  repre- 
sentee par  un  trait  continu.  En  1807,  dans  un  memoire  celebre,  et,  plus 
tard,  dans  sa  theorie  analytique  de  la  chaleur,  Fourier  montra  I'extreme 
importance  des  series  trigonometriques ;  il  a,  le  premier,  ose  affirmer  que 
toute  fonction  pouvait  etre  representee  entre  0  et  2  tt  par  un  developpe- 
ment  de  cette  nature,  et,  ce  qui  est  le  point  capital,  qu'un  meme  de- 
veloppement  pouvait  entre  ces  limites  representer  des  fonctions  qu'on 
considerait  comme  distinctes,  c'est  a  dire  correspondant  graphiquement 
a  des  arcs  de  courbes  differentes.  II  est  tres  instructif  d'etudier  dans 
la  theorie  de  la  chaleur  de  Fourier  les  voies  diverses  que  le  oelebre  geo- 
metre  a  suivies  pour  avoir  les  coefficients  du  developpement.  La  determi- 
nation de  ces  coefficients  a  I'aide  des  integrales  classiques  ne  vient  qu'en 


Premiere  Conference.  209 

second  lieu  ;  cette  determination  avait  d'ailleurs  ete  indiquee  auparavant, 
quoique  d'une  maniere  incidente,  par  Euler.     Dans  une  premiere  methode, 
Fourier  obtient  les  coefficients  en  envisageant  une  infinite  d'equations  du 
premier  degre  a  une  infinite  d'inconnues  ;  c'etait  une  recherche  audacieuse 
pour  I'epoque,  et  nous  ne  devons  pas  nous  attendre  a  trouver  dans  cette 
etude  toute  la  rigueur  que  nous  exigeons  aujourd'hui.     II  n'en  faut  pas 
moins  se  souvenir  que  Fourier  eut  le  premier  la  hardiesse  de  resoudre  des 
systemes  d'une  infinite  d'equations  lineaires  a  une  infinite  d'inconnues. 
II  y  a  d'ailleurs  en  analyse  plus  d'une  question  ou  se  presentent  de  tels 
systemes.     C'est  le  cas  quand  on  veut  chercher  le  developpement  du  quo- 
tient de  deux  series  trigonometriques,  et  aussi,  quand  ayant  a  integrer 
une  equation  differentielle  lineaire  a  coefficients  periodiques,  on  veut  y 
satisfaire  par  une  fonction  periodique  ou  au  moyen  du  produit  d'une  telle 
fonction  par  une  exponentielle ;  ce  dernier  cas  se  presente  dans  plusieurs 
problemes  de  mecanique  celeste  et  en  particulier  dans  les  beaux  travaux 
de  M.  Hill  sur  le  mouvement  du  perigee  de  la  lune.     M.  Poincare  a  pose 
les  principes  d'une  etude  rigoureuse  des  systemes  d'equations  en  nombre 
infini,  specialement  dans  le  cas  des  systemes  homogenes.     II  introduit 
dans  cette  theorie  les  determinants  d'ordre  infini,  et  un  fait  inattendu 
ressort   de  ses  recherches,  a  savoir  que  des  egalites  en   nombre   infini 
peuvent  dans  certains  cas  etre  remplacees  par  une  infinite  d'inegalites. 
II  y  a  d'ailleurs  en  analyse  bien  d'autres  questions  ou  on  se  trouve  en 
presence  d'une  infinite  d'equations  et  il  y  aura  un  jour  un  chapitre  interes- 
sant  a  ecrire  sur  I'integration  d'un  nombre  infini  d'equations  differentielles 
avec  une  infinite  de  fonctions  inconnues.     Mais  revenons  aux  series  trigo- 
nometriques.    En  poursuivant  rapidement  leur  histoire,  nous  arrivons  a 
la  periode  ou  Cauchy,  Abel,  et  Dirichlet  soumettent  a  une  revision  severe 
les  principes  fondamentaux  de  I'analyse  mathematique.     Le  memoire  de 
Dirichlet  sur  les  series   de   Fourier   est   reste   un   modele   de   rigueur ; 
I'illustre  auteur  precise  les  conditions  pour  que  Ton  puisse  affirmer  qu'un 
developpement  trigonometrique  avec  les  coefficients  de  Fourier  represente 
une  fonction  donnee  dans  I'intervalle  de  0  a  2  tt,  et  ces  conditions  sont 
restees  dans  la  science  sous  le  nom  de  conditions  de  Dirichlet.     Elles  sont 
seulement  suffisantes,  mais  on  ne  pent  esperer  dans  cette  theorie  trouver, 
sous  une  forme  pratique,  des  conditions  a  la  fois  necessaires  et  suffisantes. 
II  est  certain  aujourd'hui,  grace  surtout  aux  travaux  de  Du  Bois-Reymond, 
qu'une  fonction  continue  n'est  pas  necessairement  toujours  developpable 
en  serie  trigonometrique;  la  condition  suffisante  de  M.  Lipschitz  formulee 


210  Emile  Picard : 

par  I'inegalite  [/(a;  +  A)  — /(a;)]  <  ^A"(a  >  0),  en  designant  par  Tc  une 
constante  fixe,  a  un  grand  caractere  de  generalite,  et  il  en  est  de  meme 
du  theoreme  de  M.  Camille  Jordan  sur  la  legitimite  du  developpement 
pour  les  fonctions  a  variation  bornee. 

Le  memoire  de  Riemann  sur  les  series  trigonometriques  est  celebre 
dans  I'histoire  de  ces  series ;  on  pent  dire  en  deux  mots,  pour  le  carac- 
teriser,  qu'il  abandonne  le  point  de  vue  de  Dirichlet,  et  qu'au  lieu  de 
chercher  des  conditions  suffisantes,  sa  principale  preoccupation  est  de 
trouver  des  conditions  necessaires.  A  un  autre  point  de  vue  encore,  le 
memoire  de  Riemann  marque  une  date  parce  qu'il  continue  cette  revision 
des  principes  du  calcul  infinitesimal  commencee  par  Abel  et  Cauchy ;  la 
distinction  entre  les  fonctions  integrables  et  les  fonctions  non  integrables 
y  apparait  pour  la  premiere  fois,  et  on  pent  dire  qu'il  resulte  des  travaux 
de  Riemann  qu'il  y  a  des  fonctions  continues  n'ayant  pas  de  derivees. 

On  doit  a  M.  G.  Cantor  la  reponse  a  une  question  importante  :  une 
fonction  peut-elle  etre  representee  entre  0  et  2  tt  de  plusieurs  manieres 
par  une  serie  trigonometrique  ?  En  d'autres  termes,  zero  peut-il  etre 
represente  par  un  developpement  trigonometrique  ou  les  coefficients  ne 
soient  pas  tous  nuls  ?  Independamment  du  resultat  lui-meme,  le  memoire 
de  M.  Cantor  est  digne  d'interet  parce  que,  dans  une  question  depuis 
longtemps  posee,  des  notions  concernant  les  ensembles  de  points  viennent 
jouer  un  role  utile.  Etant  donne  un  ensemble  de  points  entre  0  et  2  tt, 
M.  Cantor  appelle  ensemble  derive  I'ensemble  de  ses  points  limites,  et 
on  pent  definir  ainsi  de  proclie  en  proche  les  derivees  successives  d'un 
ensemble.  Si  la  derivee  n^™*  d'un  ensemble  se  reduit  a  un  nombre 
limite  de  points,  I'ensemble  sera  dit  de  la  w*'"*  espece.  M.  Cantor  etablit 
que  si  dans  I'intervale  (0,  2  tt)  une  serie  trigonometrique  est  nulle  pour 
toutes  les  valeurs  de  a;  a  I'exception  de  celles  qui  correspondent  aux 
points  d'un  ensemble  d'espece  n,  pour  lequel  on  ne  salt  rien  de  la  serie 
tous  les  coefficients  seront  nuls. 

II. 

J'ai  insiste,  peut-etre  un  peu  longuement,  sur  les  series  trigono 
metriques.  Independamment  de  leur  importance  dans  les  applications 
et  particulierement  en  physique  mathematique,  elles  ont  joue  un  role 
considerable  dans  revolution  de  la  notion  de  fonction  ;  c'est  leur  etude 
qui  a  appele  I'attention  sur  des  circonstances,  qui  ne  nous  etonnent  plus 
aujourd'hui,  mais  qui   paraissaient  jadis   invraisemblables,   comma,   par 


Premiere  Conference.  211 

exemple,  ce  fait  que  la  limite  vers  laquelle  tend  una  serie  de  fonctions 
continues  pent  n'etre  pas  egale  a  la  valeur  de  la  serie  en  ce  point.  Les 
precautions  a  prendre  dans  la  derivation  des  series  ont  ete  aussi  sug- 
gerees  par  les  series  trigonometriques ;  on  pent  faire  remonter  a  cet 
exemple  les  nombreuses  recherches  effectuees  depuis  Cauchy  sur  la  deri- 
vation et  rintegration  des  series,  auxquelles  M.  Osgood  ajoutait  il  y 
a  quelques  annees  un  important  complement  dans  son  memoire  sur  la 
convergence  non-uniforme. 

Le  developpement  d'une  fonction  en  serie  trigonometrique  est  aussi 
le  type  le  plus  simple  de  developpements  tres  generaux  qui  se  presen- 
tent  dans  les  applications ;  Fourier,  ici  encore,  a  ete  un  precurseur. 
L'etude  du  refroidissement  d'une  sphere,  en  supposant  que  la  tempera- 
ture ne  depende  que  du  temps  et  de  la  distance  au  centre,  I'a  conduit 
a  un  developpement  ou,  au  lieu  des  lignes  trigonometriques  des  multiples 
x^  2  a:,  •••,  nx  de  la  variable,  figurent  les  lignes  trigonometriques  de  a^a;, 
a^,  •••,  a^p:^  les  a  designant  les  racines  en  nombre  infini  d'une  certaine 
equation  transcendante,  et  il  a  esquisse  une  theorie  de  ces  sortes  de 
developpements.  Cette  etude  a  et^  reprise  par  Cauchy  dans  plusieurs 
memoires  qui  forment  une  des  applications  les  plus  remarquables  de  ce 
que  le  grand  analyste  appelait  le  calcul  des  residus.  Sous  des  conditions 
tres  generales  relatives  a  I'equation  transcendante,  Cauchy  a  demontre 
en  toute  rigueur  la  legitimite  des  developpements  pour  une  fonction 
satisfaisant  d'ailleurs  aux  conditions  de  Dirichlet,  et  ainsi  se  sont  trouves 
considerablement  generalises  les  resultats  du  memoire  classique  de  I'il- 
lustre  geometre  allemand. 

D'autres  developpements  d'un  caractere  encore  plus  general  se  ren- 
contrent  en  physique  mathematique,  et  ont  fait  I'objet  des  travaux  de 
Poisson,  de  Sturm  et  de  Liouville  et  de  bien  d'autres,  mais  ici  se  pre- 
sentent,  au  point  de  vue  de  la  rigueur  complete,  des  difficultes  que  I'on 
a  reussi  a  surmonter  que  dans  un  petit  nombre  de  cas.  Je  citerai  seule- 
ment  I'exemple  tres  simple  du  refroidissement  d'un  mur  indefini  dont 
les  faces  extremes  sont  maintenues  a  la  temperature  zero  ;  on  suppose 
d'ailleurs  que  la  chaleur  specifique  soit  une  fonction  de  I'abscisse  x  cor- 
respondant  a  chaque  tranche,  de  telle  sorte  que  Ton  a  pour  la  tempera- 
ture V  I'equation  aux  derivees  partielles 


Tl  =  ^^^)'^' 


212  Emile  Picard : 

ou  A(x)  est  une  fonction  continue  et  positive  de  x  dans  I'intervalle  (a,  V) 
de  I'epaisseur  du  mur.     Envisageons  I'equation  lineaire  ordinaire 

et  les  valeurs  positives  de  k  en  nombre  infini,  ^j,  k^^  •••,  ^„  •••,  pour  les- 
quelles  il  existe  une  integrale  de  I'equation  precedente  s'annulant  en 
a  et  5.  A  chaque  valeur  de  k^  correspond  une  integrale  yi(x)  de  cette 
equation  (determinee  a  une  constante  pres),  et  le  probleme  qui  se  pre- 
sente  est  de  developper  une  fonction  f(x)  s'annulant  en  a  et  J  sous  la 
forme 

La  demonstration  rigoureuse  de  ce  developpement  resulte  des  der- 
nieres  recherches  de  M.  Stekloff,  s'aidant  des  travaux  anterieurs  de  M. 
Poincare  sur  les  equations  de  la  physique  matliematique.  II  semble  bien 
qu'il  soit  indispensable  pour  I'entiere  rigueur  de  supposer  que /(a;)  a  des 
derivees  des  deux  premiers  ordres  ;  nous  sommes  loin  d'atteindre  ici  a  la 
generalite  des  conditions  de  Dirichlet  pour  le  developpement  en  serie 
trigonometrique  qui  rentre  d'ailleurs  comme  cas  particulier  (celui  ou 
A(x)  est  une  constante)  dans  le  cas  precedent. 

III. 

L'histoire  des  developpements  en  series  que  je  viens  de  retracer  rapide- 
ment  nous  donne  un  remarquable  exemple  de  I'intime  solidarite  qui  unit 
a  certains  moments  I'analyse  pure  et  les  mathematiques  appliquees.  En 
plus  d'une  occasion,  ce  sont  celles-ci  qui  out  donne  I'impulsion  en  posant 
les  problemes,  et  c'est  un  fait  assurement  remarquable  que  des  questions 
concernant  les  cordes  vibrantes  ou  la  propagation  de  la  chaleur  aient 
conduit  les  geometres  a  approfondir  la  notion  si  complexe  de  fonction. 
L'histoire  de  la  science  matliematique  offrirait  d'ailleurs  des  le  debut 
des  exemples  analogues  ;  nos  facultes  d'abstraction  ne  trouvent  primi- 
tivement  a  s'exercer  qu'en  partant  de  certains  faits  concrets,  et  c'est  sans 
doute  en  reflechissant  aux  procedes  empiriques  des  praticiens  egyptiens 
leurs  predecesseurs  que  les  premiers  geometres  grecs  creerent  la  science 
geometrique.  Mais  ces  vues  risqueraient  de  m'entrainer  trop  loin,  Je 
tiens  seulement  a  aj outer  qu'il  ne  faudrait  pas  professer  une  opinion  trop 
systematique  sur  cette  marche  parallele  de  la  theorie  pure  et  des  applica- 
tions, comme  le  faisait  avec  Laplace,  Fourier,  Poisson  la  brillante  ecole 


Premiere  Conference.  213 

frangaise  de  physique  mathematique  du  commencement  de  ce  siecle. 
Pour  eux,  I'analyse  pure  n'etait  que  I'instrument,  et  Fourier,  en  annon- 
gant  a  1' Academic  des  sciences,  les  travaux  de  Jacobi,  disait  que  les  ques- 
tions de  la  philosophic  naturelle  doivent  etre  le  principal  objet  des 
meditations  des  geometres.  "  On  doit  desirer,  ajoutait-il,  que  les  personnes 
les  plus  propres  a  perfectionner  la  science  du  calcul  dirigent  leurs  tra- 
vaux vers  ces  hautes  applications  si  necessaires  au  progres  de  I'intelli- 
gence  humaine."  Ce  desir  tres  legitime  ne  doit  pas  etre  exclusif  ;  ce 
serait  meconnaitre  d'abord  la  valeur  philosophique  et  artistique  des 
mathematiques  ;  de  plus  des  speculations  theoriques  sont  restees  pendant 
longtemps  eloignees  de  toute  application,  quand  un  moment  est  venu  ou 
elles  ont  pu  etre  utilisees.  On  n'en  peut  pas  citer  d'exemple  plus 
memorable  que  le  concept  des  sections  coniques  elabore  par  les  geometres 
grecs,  qui  resta  inutilise  pendant  deux  mille  ans,  jusqu'au  jour  ou  Kepler 
s'en  servit  dans  I'etude  de  la  planete  Mars.  Les  questions  s'epuisent 
pour  un  temps,  et  il  n'est  pas  bon  que  tous  les  chercheurs  marchent  dans 
la  meme  voie.  Peu  d'annees  apres  que  Fourier  ecrivait  les  lignes  que 
je  viens  de  rappeler,  apparaissait  Evariste  Galois  qui  aurait,  s'il  avait 
vecu  davantage,  retabli  I'equilibre  en  ramenant  les  recherches  vers  les 
regions  les  plus  elevees  de  la  theorie  pure,  et  ce  fut  un  malheur  irre- 
parable pour  la  science  frangaise  que  la  mort  de  Galois,  dont  le  genie 
allait  exercer  une  action  si  profonde  sur  les  parties  les  plus  varices  des 
mathematiques. 

Avec  cette  digression,  nous  semblons  etre  bien  loin,  messieurs,  de  notre 
promenade  a  travers  I'idee  de  fonction  depuis  le  commencement  de  ce 
siecle.  Elle  n'etait  cependant  pas  inutile,  pour  montrer  qu'un  moment 
devait  arriver  ou  les  speculations  sur  la  theorie  des  f onctions  de  variables 
reelles  se  poursuivraient  sans  souci  immediat  des  applications  et  pren- 
draient  de  plus  en  plus  un  caractere  philosophique.  Nous  avons  deja  dit 
qu'il  resultait  indirectement  des  travaux  de  Riemann  qu'une  fonction  con- 
tinue n'a  pas  necessairement  une  derivee.  Weierstrass  donna  le  premier 
exemple  d'une  fonction  continue  n'ayant  de  derivee  pour  aucune  valeur 
de  la  variable,  et  il  fit  connaitre  au  sujet  des  fonctions  continues  une 
proposition  qui  nous  ramene  aux  developpements  en  series,  mais  ici  les 
termes  sont  des  polynomes.  D'apres  Weierstrass,  toute  fonction  con- 
tinue dans  un  intervalle  peut  etre  developpee  en  une  serie  de  polynomes 
qui  est  absolument  et  uniformement  convergente  dans  cet  intervalle. 
La  demonstration  de  I'illustre  geometre  est  tres  compliquee ;  elle  prend 


214  Emile  Picard : 

comme  point  de  depart  une  integrale  consideree  par  Fourier  dans  la 
theorie  de  la  chaleur,  qui  permet  d'obtenir  la  fonction  consideree  comme 
la  limite  d'une  fonction  transcendante  entiere  dependant  d'un  parametre, 
quand  celui-ci  tend  vers  zero.  C'est  de  la  que  Weierstrass  deduit  la 
possibilite  de  representer  d'une  maniere  approchee  par  un  polynome 
toute  fonction  continue  dans  un  intervalle  fini,  d'ou  se  tire  alors  de  suite 
le  resultat  enonce.  On  pent  arriver  beaucoup  plus  rapidement  au 
theoreme  de  Weierstrass  en  partant  de  I'integrale  classique  de  Poisson 
dans  la  theorie  des  series  trigonometriques ;  elle  montre  facilement  que 
la  fonction,  supposee  definie  dans  un  intervalle  moindre  que  2  tt,  peut-etre 
representee  avec  telle  approximation  que  Ton  voudra  par  une  serie 
limitee  de  Fourier,  et  on  passe  de  suite  a  une  representation  approchee 
par  un  polynome ;  celle  demonstration  s'etend  a  des  fonctions  continues 
d'un  nombre  quelconque  de  variables.  M.  Volterra  est  arrive  aussi  tres 
simplement  au  theoreme  qui  nous  occupe  en  remarquant  qu'une  fonction 
continue  est  representable  avec  telle  approximation  qu'on  voudra  par 
une  ligne  polygonale  convenable  ;  celle-ci  conduit  a  une  serie  de  Fourier 
uniformement  convergente,  et  en  la  reduisaut  a  un  nombre  suffisamment 
grand  mais  limite  de  termes  on  retombe  sur  le  resultat  indique  plus 
haut.  Le  theoreme  de  Weierstrass  presente  un  reel  interet  philosophique, 
en  meme  temps  qu'il  pent  avoir  quelque  utilite  au  point  de  vue  du  cal- 
cul  pratique ;  on  en  a  aussi  quelquefois  fait  usage  pour  la  demonstration 
de  certaines  propositions. 

Les  developpements  en  series  de  polynomes  speciaux  sont  d'un  grand 
interet,  mais  ils  ne  peuvent  s'appliquer  qu'a  des  fonctions  satisfaisant 
a  des  conditions  particulieres.  Ainsi,  dans  son  memoire  sur  I'ap- 
proximation  des  fonctions  de  tres  grands  nombres,  M.  Darboux  a 
etudie  les  developpements  d'une  fonction  suivant  les  polynomes  de  Jacobi 
provenant  de  la  serie  hypergeometrique.  Les  conditions  sont  encore 
celles  de  Dirichlet ;  pareillement  aussi  dans  le  cas  ou  la  fonction  devient 
infinie,  elle  doit  rester  integrable.  H  y  a  cependent  une  difference  quand 
la  fonction  devient  infinie  pour  les  points  extremes.  Dans  le  cas  des 
polynomes  de  Legendre,  une  fonction  qui  deviendrait  infinie  d'un  ordre 
egal  ou  superieur  a  -I  pour  x  —  ±\  ne  serait  pas  developpable,  quoique 
les  coefficients  aient  un  sens. 

IV. 

Si  nous  revenons  aux  fonctions  prises  dans  toute  leur  generalite,  on 
reconnait  vite  la  necessite  d'etablir  avec  un  soin  extreme  certaines  pro- 


Premiere  Conference.  215 

positions  que  Ton  accorde  aisement  pour  les  fonctions  usuelles.  C'est  ce 
qu'avait  deja  reconnu  Cauchy  dans  son  Analyse  algebrique ;  les  travaux 
de  Hankel,  le  memoire  de  M.  Darboux  sur  les  fonctions  discontinues,  le 
beau  livre  de  M.  Dini  et  les  etudes  plus  recentes  des  geometres  italiens 
montrent  bien  les  precautions  necessaires  dans  ce  genre  de  recherches. 
Ainsi,  une  fonction  de  deux  variables  reelles  pent  etre  continue  par  rap- 
port a  a:  et  par  rapport  a  y  sans  etre  continue  par  rapport  a  I'ensemble 
des  deux  variables,  comme  M.  Dini  en  a  indique  des  exemples.  Parmi 
les  travaux  les  plus  recents  sur  ces  questions  delicates,  je  m'arreterai  un 
instant  sur  un  memoire  de  M.  Baire  qui  renferme  de  curieux  resultats. 
L'auteur  a  reussi  a  trouver  la  condition  necessaire  et  suffisante  pour  qu'une 
fonction  fQc)  d'une  variable  reelle  puisse  etre  representee  par  une  serie 
simple  de  polynomes;  I'enonce  suppose  certaines  notions  sur  la  discon- 
tinuite  d'une  fonction  par  rapport  a  un  ensemble  de  points  :  une  fonction 
pent  etre  ponctuellement  ou  totalement  discontinue  par  rapport  a  cet 
ensemble.  La  condition  obtenne  est  que  la  fonction  soit  ponctuellement 
discontinue  par  rapport  a  tout  ensemble  parfait.  M.  Baire  se  pose  aussi 
une  question  singuliere  sur  les  equations  lineaires  aux  derivees  partielles. 
Envisageons  I'equation 

Si  je  vous  demandais  quelles  sont  les  fonctions  satisfaisant  a  cette 
equation,  vous  me  repondriez  sans  doute  que  les  fonctions  de  a;  —  y 
repondent  seules  a  la  question.  M.  Baire  n'en  est  pas  absolument  sur ; 
il  remarque  que  la  theorie  du  changement  de  variables  suppose  la  con- 
tinuite  des  derivees  qu'on  emploie ;  si  on  suppose  seulement  I'existence 

des  derivees  -^L  et  -^  de  la  fonction  cherchee  /,  on  ne  pent  pas  faire  le 
dx         dy 

changement  de  variables  classique.  II  faut  une  analyse  delicate  pour 
etablir  que  la  fonction  /,  supposee  continue  par  rapport  a  I'ensemble  des 
variables  x  et  y,  et  satisfaisant  a  (1)  est  une  fonction  diQ  x  —  y;  la  conclu- 
sion reste  douteuse  si  /  est  seulement  continue  par  rapport  a  a;  et  par 
rapport  a  y. 

Au  point  de  vue  geometrique  les  recherches  generales  sur  les  fonctions 
ne  sont  pas  non  plus  sans  interet ;  elles  nous  apprennent  a  nous  defier  de 
nos  conceptions  les  plus  simples.  Quoi  de  plus  simple  semble-t-il  qu'une 
courbe  dont  les  coordonnees  x  ety  sont  des  fonctions  continues  d'un  para- 
metre  t  variant  entre  a  et  b.     M.  Peano  a  cependant  montre  qu'on  pent 


216  Emile  Picard : 

choisir  ces  deux  fonctions  de  telle  sorte  que,  quand  t  varie  entre  a  et  5,  le 
point  (a;,  3/)  puisse  prendre  une  position  quelconque  dans  un  rectangle. 
A  certains  points  (a;,  y)  pourront  correspondre  d'ailleurs,  dans  I'exemple 
de  M.  Peano,  deux  ou  quatre  valeurs  de  t.  Ce  resultat  est  au  premier 
abord  deconcertant  ;  il  derange  nos  idees  sur  les  surfaces  et  sur  les 
courbes.  Voici  encore  un  resultat  singulier  obtenu  tout  recemment  par 
M.  Lebegue ;  il  y  a  d'autres  surfaces  que  les  surfaces  developpables  qui 
sont  applicables  sur  un  plan.  On  pent  a  Taide  de  fonctions  continues 
obtenir  des  surfaces  correspondant  a  un  plan  de  telle  sorte  que  toute  ligne 
rectifiable  du  plan  ait  pour  correspondante  une  ligne  rectifiable  de  la 
surface,  et  la  surface  n'est  cependant  pas  reglee. 

De  tels  exemples  montrent  la  subtilite  des  recherches  auxquelles 
doivent  se  livrer  aujourd'hui  ceux  qui  veulent  approfondir  la  notion  de 
fonction  prise  dans  son  extreme  generalite.  Ces  etudes  sont  en  bien  des 
points  intimement  liees  aux  speculations  sur  la  notion  meme  de  nombre. 
Nous  rejoignons  ici  une  ecole  de  philosophic  mathematique  qui  s'est 
brillamment  developpee  depuis  quelque  trente  ans,  ecole  qui  se  livre  a 
une  minutieuse  analyse  sur  la  nature  du  nombre.  On  ne  pent  s'empecher 
d'etre  frappe  du  nombre  considerable  de  publications  parues  dans  ces 
dernieres  annees  et  se  rapportant  a  cette  mathematique  philosophique ; 
elles  sont  bien  en  accord  avec  les  tendances  generales  de  I'epoque  ou  nous 
vivons,  et  ou  I'esprit  humain  applique  dans  des  directions  varices  une 
critique  de  plus  en  plus  penetrante.  Ces  speculations  raffinees  ont  meme 
penetre  dans  I'enseignement  elementaire,  ce  qui  est  a  mon  avis  tres 
regrettable.  Mais  il  ne  s'agit  pas  ici  d'enseignement ;  je  ne  recherche 
pas  non  plus  I'interet  que  ces  etudes  presentent  pour  le  philosophe  ;  il  me 
parait  tres  reel,  et  on  doit  souhaiter  que  de  jeunes  philosophes  s'engagent 
dans  cette  direction  apres  s'etre  inities  serieusement  aux  mathematiques. 
Je  ne  veux  me  placer  qu'au  point  de  vue  de  la  mathematique.  De  bons 
esprits  contestent  que  les  speculations  dont  je  parle  aient  quelque  impor- 
tance pour  les  mathematiques  positives  et  ils  craignent  de  voir  beaucoup 
de  talent  depense  dans  des  recherches  steriles.  Je  comprends  tres  bien 
leurs  craintes  mais  je  ne  partage  pas  entierement  leur  avis.  II  y  a  lieu 
sans  doute  de  faire  des  distinctions.  Certaines  questions  sont  d'un  interet 
purement  philosophique  et  n'auront  jamais  vraisemblablement  la  moindre 
utilite  pour  les  mathematiques,  comme,  par  exemple,  de  savoir  si  la  priorite 
appartient  au  nombre  cardinal  ou  au  nombre  ordinal,  c'est  a  dire  si  I'idee 
de  nombre   proprement   dit   est   anterieur   a  cells  de   rang   ou   si  c'est 


Premiere  Conference.  217 

I'inverse.  Mais  dans  d'autres  cas,  il  n'en  est  plus  de  meme ;  ainsi  il  est 
vraisemblable  que  la  theorie  des  ensembles  de  M.  Cantor,  que  nous  avons 
deja  rencontree  deux  fois  sur  notre  chemin,  est  a  la  veille  de  jouer  un 
role  utile  dans  des  problemes  qui  n'ont  pas  ete  poses  expres  pour  etre  une 
application  de  la  theorie.  Ne  regrettons  done  pas  cet  effort*  hardi  sur 
I'idee  de  nombre  et  sur  celle  de  fonction,  car  la  theorie  des  fonctions  de 
variables  reelles  est  la  veritable  base  de  I'analyse  mathematique. 


II  faut  bien,  il  est  vrai,  reconnaitre  que  la  notion  generale  de  fonction 
est  tres  vague,  et  nous  ne  pouvons  obtenir  des  resultats  de  quelque 
etendue  qu'en  faisant  des  hypotheses  particulieres.  Qu'est  ce  qui  a  guide 
plus  ou  moins  consciemment  dans  le  choix  de  ces  hypotheses  ?  II  results 
de  ce  que  nous  avons  dit  sur  les  rapports  entre  I'analyse  et  les  applica- 
tions aux  phenomenes  naturels,  que  celles-ci  ont  plus  d'une  fois  guide  le 
mathematicien  dans  son  choix.  Une  hypothese  essentielle  a  ete  celle  de 
la  continuite.  Suivant  le  vieil  adage  "natura  non  facit  saltus"  nous 
avons  le  sentiment,  on  pourrait  dire  la  croyance,  que  dans  la  nature  il  n'y 
a  pas  de  place  pour  la  discontinuite.  II  est  utile  quelquefois  de  conserver 
le  discontinu  dans  nos  calculs,  par  exemple  quand  nous  regardons  comme 
nulle  la  duree  du  choc  en  mecanique  rationnelle,  ou  quand  nous  reduisons 
a  une  surface  les  couches  de  passage  dans  plusieurs  questions  de  physique; 
mais  nous  savons  que,  pour  si  petite  qu'elle  soit,  les  chocs  ont  une  certaine 
duree  et  les  physiciens  nous  ont  appris  a  mesurer  I'epaisseur  des  couches 
ou  se  produisent  dans  plusieurs  phenomenes  des  variations  tres  rapides. 
L'idee  de  derivee  s'impose  deja  moins ;  elle  repond  cependant  au  senti- 
ment confus  de  la  rapidite  plus  ou  moins  grande  avec  laquelle  s'accomplit 
tel  ou  tel  phenomene.  L'hypothese  relative  a  la  possibilite  de  la  deriva- 
tion d'une  fonction  a  done  une  origine  analogue  a  celle  de  la  continuite. 
Je  ne  veux  pas  dire  qu'au  point  de  vue  du  nombre  l'idee  de  continuite  soit 
aussi  claire  au  fond  qu'elle  en  a  Pair,  mais  il  ne  s'agit  ici  que  de  la  notion 
du  continu  physique  tiree  des  donnees  brutes  des  sens. 

Dans  d'autres  cas,  on  ne  voit  pas  de  cause  du  meme  ordre  dans  la 
particularite  imposee  a  la  fonction ;  il  en  est  ainsi,  ce  me  semble,  pour  la 
propriete  des  fonctions  dites  analytiques  c'est  a  dire  des  fonctions  qui 
dans  le  voisinage  d'une  valeur  arbitraire  de  la  variable  peuvent  etre 
developpees  en  series  de  Taylor.  Les  fonctions  etudiees  les  premieres, 
comme  les  fonctions  rationnelles,  I'exponentielle,  les  lignes  trigonome- 


218  Emile  Picard  : 

triques,  jouissant  de  cette  propriete,  rattention  se  sera  sans  doute  trouvee 
appelee  sur  elle;  et  ensuite  la  facilite  avec  laquelle  cette  hypothese  a 
permis  d'aborder  certaines  questions  a  fait  acquerir  aux  fonctions  analy- 
tiques  une  importance  considerable.  C'est  done  a  leur  commodite  dans 
nos  calculs  qu'elles  doivent  le  grand  role  qu'elles  jouent. 

On  ne  sait  pas  d'ailleurs,  pour  une  fonction  definie  seulement  pour  les 
valeurs  reelles  de  la  variable,  quelles  sont  les  conditions  de  legitimite  du 
developpement  en  serie  de  Taylor.  Une  fonction  de  x  pent  avoir  des 
derivees  de  tout  ordre  pour  toute  valeur  de  la  variable,  et  n'etre  cependant 
pas  developpable.  On  doit  a  M.  Borel  un  resultat  remarquable  con- 
cernant  les  fonctions  d'une  variable  reelle  definie  dans  un  certain  inter- 
valle  et  ayant  dans  cet  intervalle  des  derivees  de  tout  ordre.  Si  Tintervalle 
est  (—  TT,  +7r),  la  fonction  peut  etre  representee  par  un  developpement 
de  la  forme 


I 

n=0 


(A^x"  +  Bn  cos  nx  +  O^  sin  nx"). 


Ces  diverses  remarques  m'amenent  a  dire  un  mot  d'une  ecole  de  geo- 
metres  qui  ne  veulent  rien  voir  en  dehors  des  fonctions  analytiques,  et 
d'une  maniere  plus  generale  de  I'importance,  peut-etre  exageree,  qu'a  prise 
dans  les  travaux  modernes  la  theorie  des  fonctions  analytiques.  C'est 
mutiler  singulierement  I'analyse  que  de  vouloir  se  borner  a  des  deve- 
loppements  aussi  particuliers  que  les  series  entieres,  alors  que  Ton  peut 
former  tant  de  developpements  d'une  autre  nature  qui  ne  peuvent  jamais 
etre  representees  par  de  telles  series.  Sans  doute,  les  fonctions  les  plus 
usuelles  sont  analytiques,  et  on  pourrait  nous  demander  de  citer  des 
exemples  dans  la  solution  desquels  interviennent  des  fonctions  non  analy- 
tiques, tandis  que  les  donnees  sont  analytiques.  lis  ne  sont  pas  courants  ; 
ce  sont  les  equations  aux  derivees  partielles  qui  probablement  les  four- 
niront  le  plus  facilement.  Le  suivant,  du  a  M.  Borel,  me  parait  digne 
d'etre  signale.     Envisageons  I'equation 

ou  a  est  une  irrationnelle  convenablement  choisie,  et  f(x,  y^  une  certains 
fonction  analytique  de  a;  et  y  de  periode  2  ir  pour  x  et  y.  Pour  I'equation 
de  cette  forme  citee  par  M.  Borel,  il  y  a  une  seule  solution  periodique  et 
cette  solution  n'est  pas  analytique.     Soit  a  un  nombre  incommensurable 


Premiere  Conference.  219 

tel  que  —  etant  I'une  quelconque  des  reduites  du  developpement  de  a  en 
fraction  continue,  on  ait 

on  forme 

^  (2:,  ^)  =  2  a'^i'b'^i  cos  (m^x)  cos  (yi?y')     (a  <  1,  5  <  1). 

C'est  une  fonction  non  analytique.     Posons  d'autre  part 

^-a*g  =  t(..),  (1) 

la  fonction  i/r  sera  analytique.  Done  si  on  prend  I'equation  (1)  a  priori 
et  qu'on  cherche  une  solution  periodique,  en  x  et  y,  il  n'y  en  a  qu'une ; 
c'est  <^  qui  n'est  pas  analytique. 

C'est  encore,  en  se  plagant  a  un  autre  point  de  vue,  qu'il  parait 
mauvais  de  reduire  la  theorie  des  fonctions  a  la  theorie  des  fonctions 
analytiques.  II  y  a  de  nombreuses  questions,  ou  le  fait  pour  les  donnees 
d'etre  analytiques  ne  donne  aucune  facilite  pour  la  solution,  et  ou  on 
risque,  en  portant  trop  son  attention  sur  cette  nature  des  donnees,  de 
chercher  la  solution  dans  des  voies  sans  issues.  Pour  le  probleme  du 
refroidissement  de  la  barre  dont  je  parlais  plus  haut,  qu'importe  que  les 
fonctions  donnees  A(x)  et  f(x)  soient  ou  non  analytiques  ?  Ce  n'est  pas 
tout ;  il  y  a  un  dernier  point  sur  lequel  je  tiens  a  insister.  II  pent  ar river 
que  la  circonstance  d'avoir  a  faire  a  des  fonctions  analytiques  conduise  a 
une  solution,  mais  il  se  pent  que  celle-ci  ne  se  presente  pas  sous  la  forme 
la  plus  favorable,  forme  a  laquelle  on  arrive  au  contraire  en  faisant  ab- 
straction de  la  nature  analytique  des  donnees.  La  theorie  des  equations 
differentielles  fournirait  des  exemples  a  I'appui  de  cette  assertion;  bornons 
nous  a  citer  le  theoreme  fondamental  du  Calcul  Integral  relatif  a  I'ex- 

istence  de  I'integrale  de  I'equation  differentielle  -^=f(x^y).     Ce  sont 

dx 

les  demonstrations  ne  supposant  pas  que  la  fonction  /  soit  analytique, 
qui  donnent  le  plus  grand  intervalle  comme  region  ou  I'integrale  est 
certainement  determinee ;  I'analyste,  qui  suppose  analytique  la  fonction 
reelle  f(x,  y)  et  veut  n'envisager  que  des  series  entieres,  est  conduit  par 
son  mode  de  demonstration  a  un  domaine  plus  restreint. 

J'ai  simplemeut  eu  pour  but  dans  ce  qui  precede  de  montrer  qu'il  ne 
faut  pas  restreindre  systematiquement  la  notion  de  fonction.  D'une 
maniere  generale,  admirons  des  systemes  tres  bien  ordonnes,  mais  mefions 
nous  un  pen  de  leur  apparence  scolastique,  qui  risque  d'etouffer  I'esprit 


220  Emile  Picard: 

d'invention.  II  ne  s'agit  pas,  bien  entendu,  de  nier  la  grande  importance 
actuelle  de  la  tlieorie  des  fonctions  analytiques,  mais  il  ne  faut  pas  oublier 
qu'elles  ne  forment  qu'une  classe  tres  particuliere  de  fonctions,  et  on  doit 
souhaiter  qu'un  jour  vienne  ou  les  mathematiciens  elaborent  des  theories 
de  plus  en  plus  comprehensives ;  c'est  ce  qui  arrivera  peut-etre  au  siecle 
prochain,  si  I'idee  de  fonction,  dont  je  vous  ai  bien  incompletement 
esquisse  I'histoire,  continue  son  evolution.  Mais,  pour  le  moment  nous 
sommes  encore  au  dix-neuvieme  siecle  ;  j'aurai  I'occasion  demain  et  apres 
demain  de  faire  amende  honorable  aux  fonctions  analytiques,  qui  depuis 
trente  ans  ont  fait,  comme  vous  savez,  I'objet  de  travaux  considerables. 

VI. 

Nous  venons  de  voir  les  vastes  perspectives  qu'ouvre  I'extension  de 
plus  en  plus  grande  de  la  notion  de  fonction.  II  faudra  certainement 
montrer  dans  cette  voie  beaucoup  de  prudence,  et  ne  pas  entreprendre 
avant  I'heure  des  recherches  qui  resteraient  steriles ;  mais  il  n'est  pas 
douteux  qu'un  jour  viendra  ou  I'analyste  sentira  le  besoin  d'etendre  le 
domaine  de  ses  recherches.  L'extension  de  I'idee  de  fonction  n'est  pas  la 
seule  qu'aient  poursuivie  en  ce  siecle  les  mathematiciens  qui  s'interessent 
aux  principes  de  la  science ;  la  question  des  quantites  complexes  a  vive- 
ment  excite  I'interet,  d'autant  plus  qu'une  certaine  obscurite  planait  sur 
elle,  qu'entrainait  le  mot  un  peu  mysterieux  de  quantites  imaginaires. 
Le  sujet  ne  presente  plus  rien  aujourd'hui  de  mysterieux.  Dans  un 
memoire  public  en  1884  Weierstrass  a  developpe  une  theorie  des  nombres 
complexes.     II  suppose  que  I'on  considere  des  nombres  de  la  forme 

OU  les  X  sont  des  nombres  reels  on  imaginaires  ordinaires.  Les  e  sont  de 
purs  symboles.  On  fait  Thypothese  que  la  somme,  la  difference,  le  pro- 
duit  et  le  quotient  de  deux  nombres  de  I'ensemble  font  eux-memes  partie 
de  cet  ensemble.  Les  produits  e.pe^  (^p,  q  =  1,  2,  •••,  ?i)  sont  done  des 
expressions  Up^g  lineaires  et  homogenes  en  e^,  e^^,  •••,  e„  qui  jouent  le  role 
essentiel  dans  la  theorie.  Weierstrass  suppose  de  plus  que  les  theoremes 
dits  commutatif  et  assoeiatif  subsistent  tant  pour  I'addition  que  pour  la 
mul'Liplication.  Pour  I'addition,  ils  sont  verifies  d'eux-memes  ;  pour  la 
multiplication,  ils  s'expriment  par  les  egalites 

ah  =  6a,     (ah)  .  c  =  a  •  (he). 


Premiere  Conference.  221 

a,  5,  c  etant  trois  nombres  quelconques  de  I'ensemble.  Ces  conditions 
conduisent  a  certaines  relations  entre  les  coefficients  des  formes  lineaires 
I^p^q.  A  tout  systeme  de  formes  E^^^  verifiant  ces  conditions  corre- 
spondra  un  ensemble  de  nombres  complexes.  Les  nombres  complexes 
que  nous  venons  de  definir  different  seulement  en  un  point  des  nombres 
complexes  ordinaires.  Quand  n  est  superieur  a  deux,  il  pent  exister  des 
nombres  differents  de  zero  dont  le  produit  par  certains  autres  nombres 
est  nul.  Weierstrass  appelle  ces  nombres  des  diviseurs  de  zero.  M. 
Dedekind  a  montre  qu'en  general  les  calculs  avec  ces  nombres  complexes 
se  ramenaient  aux  calculs  de  I'algebre  ordinaire ;  d'une  maniere  plus 
precise,  si  le  carre  d'un  nombre  ne  pent  etre  nul  sans  que  ce  nombre  soit 
nul,  on  pent  aux  n  unites  complexes  primitives  substituer  n  autres  unites 
(le  determinant  de  la  substitution  n'etant  pas  nul)  de  telle  sorte  que  pour 
ces  nouvelles  unites  e\^  e'^,  •■•,  e'„,  on  ait 

d'ou  Ton  conclut  que  les  calculs  relatifs  aux  nombres  complexes  prece- 
dents se  ramenent  a  des  calculs  relatifs  aux  nombres  reels  ou  complexes 
ordinaires. 

Nous  avons  admis  que  les  lois  commutative  et  associative  subsis- 
taient  dans  I'algebre  precedente.  On  s'est  place  a  un  point  de  vue  plus 
general  en  supposant  que,  seule,  la  loi  associative  subsistait  [c'est  a  dire 
(ah)c  =  a(hc)'].  On  a  alors  une  algebre  beaucoup  plus  generale  ;  celle-ci 
est  completement  determinee  par  le  systeme  des  expressions  lineaires 
Ep^q.  Un  exemple  celebre  d'un  systeme  a  quatre  unites  e^,  e^^  e^,  e^  est 
fourni  par  les  quaternions  d' Hamilton 

gj  =  ±,     62^^*5     ^3  ^  ^'     ^4  ^^    ' 
avec  les  relations  t^  =  p  =  k^  z=  —1 

ij  =  -  ji  =  k 
jk  =  —  kj  =  i 
ki  =  —  ik  =  j. 

Une  remarque  tres  interessante  de  M.  Poincare  ramene  toute  la 
theorie  des  quantites  complexes  a  une  question  concernant  la  theorie  des 
groupes.  Elle  consiste  en  ce  qu'a  chaque  systeme  d'unites  complexes 
correspond  un  groupe  continu  (au  sens  de  Lie)  de  substitutions  lineaires 


222  Emile  Picard : 

a  n  variables,  dont  les  coefficients  sont  des  fonctions  lineaires  de  n  para- 
metres  arbitraires,  et  inversement.  Cette  idee  a  ete  approfondie  par 
M.  Scheffers  qui  a  ete  ainsi  conduit  a  partager  les  nombres  complexes 
en  deux  classes,  suivant  que  le  groupe  qui  leur  correspond  est  integrable 
ou  non  integrable.  A  cette  derniere  classe  appartient  le  groupe  corres- 
pondant  aux  quaternions,  et  ceux-ci  sont  les  representants  les  plus  simples 
de  cette  categoric  de  nombres  complexes.  Le  rapprochement  entre  la 
theorie  des  groupes  de  Lie  et  les  nombres  complexes  fait  disparaitre 
le  mystere  qui  semblait  planer  sur  ceux-ci,  et  la  veritable  origine  des 
symboles  est  ainsi  bien  mise  en  evidence.  On  pent  se  demander  si  ce 
symbolisme  est  susceptible  d'accroitre  la  puissance  de  I'Analyse.  En 
France,  les  geometres  qui  s'interessent  a  ces  calculs  sont  tres  peu  nom- 
breux  ;  je  sais  qu'au  contraire  en  Angleterre  et,  je  crois  aussi,  dans  ce 
pays  les  quaternions  sont  tres  apprecies.  Je  ne  les  ai  pas  assez  manies 
moi-meme,  pour  me  rendre  compte  si  leur  emploi  en  mecanique  ou  en 
physique  mathematique  simplifie  les  calculs  d'une  maniere  tres  appre- 
ciable ;  il  y  a  probablement  la  surtout  une  affaire  d'habitude.  Le  point 
vraiment  interessant  serait  de  savoir  si  ces  quantites  complexes  presen- 
teront  un  jour  quelque  interet  pour  I'analyse  generale,  comme  il  arrive 
pour  les  imaginaires  ordinaires.  Les  essais  tentes  jusqu'ici  dans  cette  voie 
ne  paraissent  pas  avoir  ete  heureux ;  mais,  maintenant  que  le  lien  avec 
la  theorie  des  groupes  est  completement  mis  en  evidence,  il  n'est  pas 
impossible  que  de  nouvelles  tentatives  n'aboutissent  a  quelque  resultat 
interessant. 

Les  idees  de  nombres  reel  ou  complexe,  la  notion  de  fonction  sont 
a  la  base  meme  de  I'analyse  ;  il  y  a  encore  une  autre  notion  que  le  travail 
mathematique  de  ce  siecle  a  conduit  a  elargir  considerablement.  L'idee 
d'espace  forme  la  matiere  meme  de  la  geometric  ;  elle  aussi  a  ete  sou- 
mise  a  une  critique  penetrante  qui  a  renouvele  les  bases  de  la  geometric. 
Je  n'en  referai  pas  I'histoire  depuis  Gauss,  Bolyai  et  Lobatschevski,  his- 
toire  tres  souvent  racontee,  ni  ne  prendrai  parti  dans  les  querelles  que 
se  font  encore  a  ce  sujet  les  philosophes.  Je  veux  dire  seulement  un 
mot  de  I'interet  qu'ont  eu  pour  les  mathematiques  les  speculations  sur 
la  nature  de  I'espace.  Dans  le  memoire  cel^bre  de  Riemann,  apparaissent 
pour  la  premiere  fois  les  notions  relatives  a  la  courbure  de  I'espace  dans 

les  differentes  directions,  c'est-a-dire  les  — ^^ — ^ — -  fonctions  invariantes 

caracteristiques  d'une  multiplicite  a  n  dimensions  ;    une  vive  impulsion 


Preiniere  Conference.  223 

a  ete  ainsi  donnee  a  la  theorie  des  formes  quadratiques  de  differentielles. 
Pour  ne  citer  qu'un  exemple,  j'indiquerai  seulement  la  forme 

dx^  +  dy^ 

qui  donne  le  carre  de  Felement  d'arc  dans  la  geometric  de  Lobatchevski ; 
et  il  est  interessant  de  rappeler  le  role  qu'elle  a  joue  dans  les  recherches 
de  M.  Poincare  sur  la  formation  des  groupes  fuchsiens.  Apres  Rie- 
mann,  Helmholtz  posa  la  question  sur  un  autre  terrain:  son  idee  fonda- 
mentale  consiste  a  porter  I'attention  sur  I'ensemble  des  mouvements 
possibles  dans  I'espace  dont  on  fait  I'etude.  Le  grand  physicien  traitait 
ainsi  par  avance  de  problemes  se  rattacbant  a  la  tbeorie  des  groupes. 
Celle-ci  n'etait  pas  encore  creee  a  I'epoque  ou  Helmboltz  ecrivait  son 
memoire ;  il  a  commis  quelques  erreurs  apres  tout  secondaires,  mais 
il  n'en  a  pas  moins  la  gloire  d'avoir  le  premier  regarde  une  geometric 
comme  I'etude  d'un  groupe.  Les  recherches  d'Helmholtz  furent  reprises 
completement  par  Lie  ;  elles  lui  offraient  une  magnifique  occasion  d'ap- 
pliquer  son  admirable  theorie  des  groupes  de  transformations.  Dans 
ces  etudes,  I'espace  est  a  priori  regarde  comme  une  multiplicite,  et,  en 
prenant  le  cas  de  trois  dimensions,  un  point  est  defini  par  trois  quantites 
(r»,  ?/,  z).  Un  mouvement  dans  I'espace  n'est  autre  chose  qu'une  trans- 
formation 

x^  =f(x,  y,  z),  y^  =  <^(x,  y,  2),  z'  =  -^(x,  y,  2) 

valable  pour  une  portion  de  I'espace.  On  suppose  que  tous  les  mouve- 
ments possibles  forment  un  groupe  a  six  parametres,  qu'ils  laissent 
invariable  une  fonction  des  coordonnes  de  deux  points  quelconques, 
qu'enfin  le  mouvement  libre  soit  possible,  comme  disait  Helmholtz.  Lie 
demontre  alors  que  I'espace  euclidien  et  les  espaces  non  euclidiens  sont 
les  seuls  qui  satisfassent  a  ces  conditions.  Au  point  de  vue  ou  s'est  place 
Lie,  I'etude  des  principes  de  la  geometric  pent  etrc  regardee  comme 
epuisee,  mais  il  se  borne  a  considerer  une  petite  portion  de  Tespacc. 
Clifford  et  Klein  ont  appele  I'attention  sur  la  question  de  la  connexite  de 
I'espace  qui  est  extremement  interessante  ;  nous  nc  savons  rien  sur  la 
connexite  de  I'espace  ou  nous  vivons.  On  pent  aussi  chercher  a  appro- 
fondir  le  postulat  de  I'espace  regarde  comme  une  multiplicite,  et  sub- 
ordonner  la  conception  metrique  dc  I'espace  a  la  conception  projective 
avec  von  Staudt,  Cayley  et  Klein  ;  mais  je  dois  me  contenter  de  rappeler 
ces  directions  diverses. 


224  Emile  Picard : 

J'ai  seulement,  messieurs,  voulu  montrer  dans  cette  conference  quelles 
perspectives  ouvre  aux  chercheurs  I'extension  de  nos  idees  sur  les  fonc- 
tions,  sur  le  nombre  et  sur  I'espace.  Si  I'elaboration  mathematique  est 
aussi  feconde  au  siecle  prochain  qu'elle  Fa  ete  en  ce  siecle,  I'analyse 
differera  beaucoup  dans  cent  ans  de  ce  qu'elle  est  aujourd'hui ;  on 
maniera  peut-etre  couramment  les  fonctions  les  plus  extraordinaires,  et 
on  verra  tres  clair  dans  des  espaces  ayant  beaucoup  de  dimensions  et  des 
connexites  elevees.  Pour  se  representer  I'etat  de  la  mathematique  en 
Fan  2000,  il  faudrait  I'imagination  de  I'auteur  de  "Looking  Backward"; 
il  est  mallieureux  que  M.  Bellamy  dans  son  roman  ne  nous  ait  pas  parle 
des  mathematiques  a  cette  epoque.  Comme  I'humanite,  s'il  faut  Ten 
croire,  aura  alors  beaucoup  de  loisirs,  les  mathematiques  seront  sans 
doute  extremement  florissantes  et  les  problemes  qui  nous  arretent  aujour- 
d'hui ne  seront  plus  que  des  jeux  d'enfants  pour  nos  successeurs. 

Secondb  Conference. 

Quelques  Vues  GenSrales  sur  la  Theorie  des  Equations  DiffSrentielles. 

Je  voudrais  aujourd'hui  jeter  un  coup  d'oeil  sur  la  theorie  des  equa- 
tions differentielles,  qui  joue  en  analyse  un  role  considerable  et  dont  les 
progres  importent  vivement  a  ses  applications;  c'est  un  domaine  tres 
vaste  et  j'eprouve  quelque  embarras  a  faire  un  choix  entre  les  directions 
si  diverses  ou  s'est  developpee  cette  theorie.  Les  geometres  du  siecle 
dernier  ne  paraissent  pas  s'etre  preoccupes  d'etablir  rigoureusement 
I'existence  des  integrales  des  equations  differentielles;  ils  integraient, 
quand  ils  le  pouvaient,  les  equations  qui  se  presentaient  dans  leurs 
recherches,  sans  se  soucier  de  ces  theorem es  d'existence,  comme  on  dit 
aujourd'hui,  auxquels  nous  attachons  beaucoup  d'importance.  C'est  a 
Cauchy  que  Ton  doit  les  premieres  recherches  precises  sur  ces  questions ; 
le  champ  en  est  tres  vaste,  et  il  ne  I'a  pas  parcouru  en  entier,  mais,  au 
moins  dans  le  cas  oii  les  fonctions  et  les  donnees  sont  analytiques,  il 
a  indique  les  principes  qu'ont  suivis  tons  ses  continuateurs.  Dans  les 
theoremes  relatifs  a  I'existence  des  integrales,  on  emploie  des  methodes 
differentes  suivant  que  les  equations  et  les  donnees  sont  supposees  on  non 

analytiques. 

I. 

Plagons  nous  d'abord  dans  le  premier  cas,  de  beaucoup  le  mieux 
elabore.     L'idee  essentielle  de  Cauchy  consiste  dans  la  consideration  des 


Seconde  Conference.  225 

fonctions  majorantes.  On  salt  que  les  difficultes  resident  surtout  dans 
la  demonstration  de  la  convergence  de  certaines  series  entieres  que  les 
equations  differentielles  permettent  de  former.  Cauchy  y  parvient  par 
des  comparaisons  avec  d'autres  equations  facilement  integrables.  Pour 
les  equations  differentielles  ordinaires,  il  n'y  avait  a  faire  apres  Cauchy 
que  des  simplifications  de  forme,  et,  pour  le  cas  d'une  seule  equation  aux 
derivees  partielles,  quel  que  soit  le  nombre  des  variables,  le  grand  geo- 
metre  avait  indique  aussi  les  points  essentiels  de  la  demonstration,  que 
Mme.  Kovalevski,  dans  un  memoire  reste  classique,  a  presentee  sous  une 
forme  tres  simple.  Le  tbeoreme  fondamental  est  alors  le  suivant :  Si  on 
a  une  equation  aux  derivees  partielles  d'ordre  n  relative  a  une  fonction 
2  de  j9  +  1  variables  independantes  x,  x^,  •••,  Xp  et  que  I'equation  con- 

tienne  la  derives  d'ordre  w,  — ,  une  integrale  sera  en  general  determinee 

dx"" 

si  on  se  donne  pour  x  =  a  les  valeurs  de  z  et  de  ses  derivees  par  rapport 

a  x  jusqu'a  I'ordre  n  —  1 ;  ces  donnees  sont  des  fonctions  holomorphes  de 

x^,  2^2'  '••'  ^p  ^^"s  ^^  voisinage  de  a^  a^,  •-,  a^.     On  pent  done  dire,  en 

s'appuyant  sur  cet  enonce  que  I'integrale  generale  de  I'equation  consideree 

depend  de  n  fonctions  de  p  variables  independantes.     C'etait  un  point 

auquel  on  tenait  beaucoup  autrefois  de  savoir  de  combien  de  fonctions 

arbitraires   dependait   I'integrale  generale   d'une   equation  aux  derivees 

partielles  ;    certains  resultats  paradoxaux  avaient  cependant  deja  appele 

I'attention  comme  les  formes  diverses  de  I'integrale  generale  de  I'equation 

de  la  chaleur   —  =  — ,  qui  se  presentait  tantot  avec  une,  tantot  avec 
dx^       By 

deux  fonctions  arbitraires.  De  tels  resultats  ne  nous  etonnent  plus 
aujourd'hui,  quand  il  s'agit  comme  ici  de  fonctions  analytiques.  Nous 
n'avons  qu'a  nous  rappeler  qu'un  nombre  fini  quelconque  de  fonctions  a 
un  nombre  quelconque  de  variables  independantes  ne  presente  pas,  au 
point  de  vue  arithmetique,  une  plus  grande  generalite  qu'une  seule  fonc- 
tion d'une  seule  variable,  puisque  dans  I'un  et  I'autre  cas  I'ensemble  des 
coefficients  des  developpements  forme  simplement  une  suite  enumerable. 
Aussi  s'explique-t-on  que  M.  Borel  ait  pu  etablir  que  toute  integrale 
analytique  d'une  equation  aux  derivees  partielles  a  coefficients  analy- 
tiques pent  etre  exprimee  a  I'aide  d'une  formule  ne  renfermant  qu'une 
seule  fonction  arbitraire  d'une  variable  reelle. 

Nous  venous  de  considerer  une  seule  equation  aux  derivees  partielles. 
L'etude  des  systemes  d'equations  differentielles  presentait  de  plus  grandes 


226  Emile  Pimrd : 

difficultes.  Une  premiere  question  est  tout  d'abord  restee  longtemps 
sans  reponse  ;  il  etait  possible  de  se  demander  s'il  pouvait  exister  des 
systemes  qui  comprennent  un  nombre  illimite  d'equations  distinctes  c'est 
a  dire  ne  pouvant  pas  se  deduire  par  differentiation  d'un  certain  nombre 
d'entre  elles.  M.  Tresse  a  etabli  qu'un  systeme  d'equations  aux  derivees 
partielles  etant  defini  d'une  maniere  quelconque,  ce  systeme  est  necessaire- 
ment  limite,  c'est  a  dire  qu'il  existe  un  nombre  fini  s,  tel  que  toutes  les 
equations  d'ordre  superieur  a  s,  que  contient  le  systeme,  se  deduisent  par 
de  simples  differentiations  des  equations  d'ordre  egal  ou  inferieur  a  s. 
II  importait  ensuite  de  se  rendre  compte  de  la  nature  des  elements 
arbitraires  figurant  dans  I'integrale  generale.  Mme.  Kovalevski  n'avait 
examine  que  certains  systemes  composes  d'equations  en  nombre  egal  a 
celui  des  fonctions  inconnues  et  resolubles  par  rapport  aux  derivees 
d'ordre  le  plus  eleve  de  chacune  des  fonctions,  ces  derivees  etant  relatives 
a  une  meme  variable  x.  M.  Riquier  d'abord,  puis  M.  Delassus  ont  donne 
sous  des  formes  differentes  la  solution  du  probleme  dans  le  cas  general ; 
M.  Delassus  arrive  par  des  changements  de  variables  a  obtenir  une  forme 
canonique  completement  integrable,  et  montre  que  I'integration  d'un  tel 
systeme  a  m  variables  se  ramene  a  I'integration  successive  de  m  systemes 
de  Mme.  Kovalevski  contenant  successivement  1,  2,  •••,  m  variables;  c'est 
en  partant  de  cette  propriete  qu'on  pent  demontrer  facilement  I'existence 
des  integrales  analytiques,  et  determiner  les  fonctions  et  constantes 
initiales  en  nombre  fini  dont  dependent  ces  integrales. 

II  semble  y  avoir  eu  longtemps  chez  les  mathematiciens  quelques  hesi- 
tations sur  ce  qu'on  devait  entendre  par  integrale  generale  d'une  equation 
aux  derivees  partielles.  Si  I'on  se  borne  aux  cas  ou  il  ne  figure  dans  les 
equations  que  des  elements  analytiques,  et  si  I'on  n'envisage  que  les  inte- 
grales analytiques,  on  considere  aujourd'hui,  conformement  a  I'opinion 
de  M.  Darboux,  qu'une  integrale  est  generale,  si  on  pent  disposer  des 
arbitraires  qui  y  figurent,  fonctions  et  constantes,  de  maniere  a  retrouver 
les  solutions  dont  les  theoremes  de  Caucliy  et  de  ses  successeurs  nous  ont 
demontre  I'existence.  Anterieurement,  Ampere  s'etait  place  a  un  autre 
point  de  vue ;  dans  son  grand  memoire  sur  les  equations  aux  differences 
partielles,  il  s'exprime  ainsi :  "  Pour  qu'une  integrale  soit  generale,  il  faut 
qu'il  n'en  resulte  entre  les  variables  que  I'on  considere  et  leurs  derivees  a 
I'infini  que  les  relations  exprimees  par  I'equation  donnee  et  par  les  equa- 
tions que  I'on  en  deduit  en  la  differentiant."  II  est  bien  clair  qu'il  s'agit 
de  relations  ne  renfermant  aucune  des  quantites  arbitraires  qui  figurent 


Seconde  Conference.  227 

dans  Fintegrale  consideree.  Les  avis  etaient  partages  entre  les  geometres, 
et  on  se  demandait  s'il  y  a  identite  entre  la  definition  d' Ampere  et  celle 
de  Cauchy.  M.  Goursat  a  montre  bien  nettement,  sur  differents  exemples, 
qu'une  integrale  pent  etre  generale  au  sens  d' Ampere  sans  etre  generale 
an  sens  de  Cauchy. 

II  ne  faudrait  pas  conclure  des  divers  travaux  qui  precedent,  que,  tout 
en  envisageant  seulement  des  integrales  et  des  equations  analytiques, 
I'etude  des  conditions  determinant  les  integrales  d'un  systeme  d'equations 
aux  derivees  partielles  soit  actuellement  achevee.  Les  theoremes  generaux 
indiques  font  connaitre  certaines  donnees  qui  determinent  une  integrale, 
mais  celle-ci  pent  etre  determinee  par  une  infinite  d'autres  conditions.  II 
n'est  pas  douteux  que  les  types  a  trouver  de  ces  theoremes  d'existence 
sent  en  nombre  infini.     Prenons  I'exemple  tres  simple  de  I'equation 

•\-  a f-o-— -+C2  =  U. 


bx  by  dx  dy 

Une  integrale  est  determinee  par  la  condition  de  se  reduire  pour  x=0 
a  une  fonction  domiee  de  y^  et  pour  ?/  =  0  a  une  fonction  donnee  de  x : 
voila  un  genre  de  determinations  d'une  integrale  qui  ne  rentre  pas  dans 
les  conditions  du  theoreme  general  de  Cauchy.  Les  conditions  tres 
varices,  qui  peuvent  determiner  les  integrales  des  equations  aux  dif- 
ferences partielles  appellent  encore  de  nombreuses  recherches. 


n. 

Nous  venous  de  nous  placer  au  point  de  vue  de  la  theorie  des  fonctions 
analytiques.  Comme  je  le  disais  hier,  il  y  a  souvent  grand  iuteret,  non 
seulement  a  un  point  de  vue  philosophique,  mais  meme  en  quelque  sorte 
au  point  de  vue  pratique,  a  adopter  des  hypotheses  plus  generales.  C'est 
encore  a  Cauchy  que  Ton  doit  pour  les  equations  differentielles  ordinaires 
la  demonstration  de  I'existence  des  integrales  sans  supposer  les  equations 
analytiques.  Sa  methode,  bien  naturelle  et  bien  simple,  consiste  a 
regarder  les  equations  differentielles  comme  limites  d'equations  aux 
differences.  On  pent  faire  sur  cette  methode  de  Cauchy  une  remarque 
tres  interessante ;  elle  est  susceptible  de  fournir  des  developpements  en 
series  des  integrales  qui  convergent  tant  que  les  intSgrales  restent  continues^ 
et   laissent  continues   les   coefficients    differentiels.      En    ce   sens,   elle  est 


228  Emile  Picard : 

superieure  aux  autres  methodes  qui  ont  ete  proposees.  Ainsi,  pour 
prendre  un  exemple,  soit  le  systeme  d'equations 

-^  =  Xi(x^,  x^,  •••,  x^       {i  =  1,  2, ...  w) 

ou  les  X  sont  des  polynomes.  On  pent  representer  les  integrales  de 
ce  systeme  prenant  pour  i=  0  les  valeurs  x-^^  x^^  •••,  x^  par  des  deve- 
loppements  de  la  forme 

les  P  etant  des  polynomes  en  x^^x^^  '-'iX^  et  t,  et  ces  developpements 
sont  convergents  tant  que  les  integrales  restent  des  fonctions  continues 
de  t. 

D'autres  methodes  ont  ete  proposees  pour  demontrer  I'existence  des 
integrales,  comme  la  methode  des  approximations  successives  qui  donne 
pour  les  series  une  convergence  tres  rapide,  mais  ces  series  ne  convergent 
pas  necessairement  dans  tout  le  champ  ou  les  integrales  sont  continues. 

Pour  une  equation  differentielle  ordinaire  d'ordre  w,  on  suppose 
generalement,  quand  on  veut  etablir  I'existence  des  integrales,  qu'on  se 
donne  pour  une  valeur  de  x  les  valeurs  de  la  fonction  et  de  ses  derivees 
jusqu'a  I'ordre  n  —  1,  mais  on  pourrait  prendre  beaucoup  d'autres  don- 
nees;  et  c'est  ce  qui  arrive  notamment  dans  les  applications  du  calcul 
des  variations.  Ainsi  pour  une  equation  du  second  ordre,  il  arrive  qu'une 
integrale  soit  determinee  par  les  conditions  de  prendre  pour  x^  la  valeur 
3/q  et  pour  x-^  la  valeur  y^  On  a  peu  travaille  jusqu'ici  dans  cet  ordre 
d'idees,  et  cependant  maintes  conditions  initiales  sont  aussi  interessantes 
que  celles  adoptees  dans  le  theoreme  general  classique.  Les  recherches 
entreprises  dans  cette  voie  ont  conduit  a  quelques  resultats  par  I'emploi 
de  methodes  d'approximations  successives,  et  on  a  pu  ainsi  reconnaitre  des 
cas  singuliers  de  divergence  dans  I'emploi  de  ces  methodes  d'approximation. 

Si  nous  passons  maintenant  aux  equations  aux  differences  partielles, 
les  equations  et  les  donnees  n'etant  pas  necessairement  analytiques,  nous 
nous  trouvons  dans  un  domaine  tres  etendu  ou  on  n'a  fait  que  les  pre- 
miers pas.  II  faut  deja  quelque  soin  pour  etablir  I'existence  des  inte- 
grales de  I'equation  lineaire 


Seconde  Conference.  229 

sans  supposer  que  X(x^  y)  soit  analytique.  Pour  les  equations  d'ordre 
superieur,  il  n'y  a  qu'un  petit  nombre  de  types  pour  lesquels  on  puisse 
definir  avec  precision  ce  que  Ton  entend  par  integrale  generale.  lis  ont 
generalement  pour  origine  des  problemes  de  geometrie  infinitesimale 
ou  de  physique  mathematique  ;  les  variables  et  les  fonctions  restent  ici 
reelles.     Prenons,  comme  exemple,  I'equation 

b'^z  dz       ^dz  ^ 

+  a—  +  b—  +  cz  =  0 


dxdy         dx         dy 

ou  «,  J,  c  sont  des  fonctions  continues  de  x  et  y^  sur  laquelle  Riemann 
a  ecrit  quelques  pages  extremement  remarquables.  Soit  un  arc  de 
courbe  MP  tel  que  toute  parallele  a  Oa;  et  a  Oy  le  rencontre  au  plus  en 

dz 
un  point ;    nous  nous  donnons  les  valeurs  de  2  et  —  sur  cette  courbe. 

II  y  aura  une  integrale  et  une  seule,  continue  ainsi  que  ses  derivees 
partielles  du  premier  ordre,  satisfaisant  aux  conditions  donnees,  et  elle 
sera  definie  dans  le  rectangle  de  cotes  paralleles  aux  axes  et  ayant  M  et  P 
pour  sommets  opposes.  On  voit  combien  cet  enonce  est  d'une  nature 
plus  precise  que  ceux  qui  ont  ete  donnes  anterieurement  en  nous  plagant 
au  point  de  vue  de  la  theorie  des  fonctions  analytiques,  ou  pour  une 
equation  comme  celle-ci  on  etablit  seulement  I'existence  d'une  solution 
dans  le  voisinage  d'une  courbe,  voisinage  determine  avec  tres  peu  de 
precision.  L'exemple  si  simple  que  nous  avons  choisi  montre  encore 
qu'il  n'existe  pas  toujours  d'integrale  continue  ainsi  que  ses  derivees 
premieres  satisfaisant  aux  conditions  donnees  sur  un  arc  de  courbe  ; 
il  en  sera  ainsi  quand  sur  cet  arc  il  y  aura  une  tangente  parallele  a  I'un 
des  axes.     Voici  un  second  exemple  dans  le  meme  ordre  d'idees  ;  on  pent 

relativement  a  I'equation 

d'^u      B'^u     d^u  _  „ 
dx^      dy'^      dz^ 

die 
se  donner  les  valeurs  de  w  et  de  ^  pour  les  points  d'un  cercle  0  situe 

dans  le  plan  z  =  z^;  I'integrale  ainsi  definie  est  determinee  a  I'interieur 
des  deux  cones  de  revolution  passant  par  la  circonference  0  et  de  gene- 
ratrices paralleles  a  celles  du  cone  x^  -{-  y^  —  z^  =  0. 

Les  conditions  determinant  une  integrale  peuvent  prendre  des  formes 
tres  diverses.  Ainsi  des  conditions  de  continuite  sont  susceptibles  de 
remplacer   certaines  donnees  :    c'est   un   fait   auquel   nous  sommes  tres 


230  Emile  Picard : 

habitues,  mais  qui  n'en  est  pas  moins  tres  remarquable.  L'equation  du 
potentiel  a  provoque  dans  cette  voie  de  nombreuses  reclierclies,  et  le 
theoreme  fondamental  auquel  Riemann  a  donne  le  nom  de  Diricblet, 
apres  avoir  ete  approfondi  par  Schwarz  et  Neumann,  a  encore  fait  recem- 
ment  I'objet  des  recherches  de  M.  Poincare.  Des  problemes  analogues 
ont  ete  poses  et  resolus  pour  un  grand  nombre  d'equations,  par  exemple 
pour  l'equation 

S^M      d^u        du      ,  du  -, 

Fl  +  r~2  +  ^T'  +  ^T"  -I-  cw  =  0 
ox^      ay^        ox        By 

pour  laquelle  une  integrale  continue  est  determinee  par  ses  valeurs  sur 
un  contour  ferme  dans  toute  region  ou  le  coefficient  c  est  negatif  ;  de 
telles  questions  ne  sont  d'ailleurs  pas  limitees  aux  equations  lineaires. 

Ces  divers  exemples  caracterisent  bien  la  nature  des  theoremes  d'exis- 
tence  des  integrales,  quand  on  ne  se  place  pas  au  point  de  vue  de  la 
theorie  des  fonctions  analytiques.  II  y  a  la  un  ordre  immense  de  re- 
cherches egalement  interessantes  pour  la  theorie  pure  et  pour  les  appli- 
cations de  I'analyse.  Sans  meme  aborder  de  questions  entierement 
nouvelles,  que  de  points  seraient  a  reprendre  dans  les  travaux  celebres 
des  physiciens  geometres  de  la  premiere  moitie  du  siecle,  de  Fourier, 
de  Poisson,  de  Cauchy  meme,  si  on  voulait  y  apporter  la  rigueur  que 
Ton  exige  aujourd'hui  en  mathematiques. 

Je  dois  aj outer  d'ailleurs,  comme  transition  entre  les  deux  directions 
relatives  aux  generalites  sur  les  equations  aux  derivees  partielles,  qu'il 
existe  des  classes  tres  etendues  d'equations  dont  toutes  les  integrales  sont 
analytiques.  Citons  les  equations  lineaires  d'ordre  n  a  deux  variables 
independantes  :  dans  une  region  du  plan  ou  toutes  les  caracteristiques 
sont  imaginaires,  toute  integrale  bien  determinee  et  continue  ainsi  que 
ses  derivees  partielles  jusqu'a  I'ordre  n  est  necessairement  analytique. 
II  y  a  aussi  de  nombreuses  equations  non  lineaires  ayant  toutes  leurs 
integrales  analytiques. 

Je  viens  de  parler  des  caracteristiques  d'une  equation  ;  c'est  la  un 
sujet  en  connexion  etroite  avec  les  theoremes  generaux  d'existence  qui 
viennent  de  nous  occuper.  Les  caracteristiques  sont  certaines  multipli- 
cites  jouissant  de  proprietes  particulieres  relativement  a  une  equation 
donnee,  multiplicites  singulieres  en  ce  qu'elles  ne  definissent  pas  une 
integrale  contrairement  a  ce  qui  arrive  en  general  pour  les  multiplicites 
contenant  les  memes  elements.     Tandis  que  la  notion  de  caracteristiques 


Seconde  Conference.  231 

est  aujourd'hui  tres  nette  pour  les  equations  ou  systemes  d'equations  a 
deux  variables  independantes,  elle  a  encore  besoin  d'etre  approfondie  dans 
le  cas  de  plus  de  deux  variables. 

III. 

Si,  quittant  les  generalites  relatives  a  I'existence  des  integrales,  nous 
voulons  parler  de  la  recherche  effective  des  integrales  et  de  I'etude 
d'equations  particulieres,  I'embarras  est  grand  de  tenter  des  classifica- 
tions dans  un  ensemble  considerable  de  travaux,  et  nous  sentons  combien 
nos  classements  sont  tou jours  defectueux  par  quelque  endroit.  Peut-etre 
pourrait-on  tout  d'abord  distinguer  I'ancienne  ecole  mathematique,  et  le 
mot  ^'■ancienne^^  ne  veut  pas  dire  qu'elle  ne  continue  pas  a  prosperer. 
C'est  I'Ecole  d'Euler,  de  Lagrange,  de  Monge  dans  son  immortel  ouvrage 
sur  les  applications  de  I'analyse  a  la  geometric,  d' Ampere  dans  son  celebre 
memoire  de  1817  sur  les  equations  aux  differences  partielles.  En  France, 
cette  ecole  des  analystes  geometres  pour  qui  les  problemes  de  geometric 
infinitesimale  sont  I'occasion  de  belles  recherches  analytiques,  a  pour  chef 
M.  Darboux.  Ses  Legons  sur  la  Thdorie  des  surfaces  sont  aujourd'hui 
un  livre  classique  qui  a  rappele  I'attention  sur  des  questions  quelque 
temps  negligees.  Relativement  a  I'integration  effective  des  equations  du 
second  ordre,  pendant  de  longues  annees  apres  la  publication  du  memoire 
d'Ampere,  il  n'avait  ete  rien  ajoute  d'essentiel  a  la  theorie  developpee  par 
le  grand  geometre.  En  1870,  M.  Darboux  publia  un  memoire  renfermant 
des  vues  profondes  et  originales  qui  est  fondamental  dans  I'histoire  de 
cette  theorie.  Depuis  cette  epoque,  divers  geometres  ont  developpe  des 
methodes  plus  ou  moins  analogues.  M.  Goursat  vient  de  rassembler  dans 
un  ouvrage  considerable  les  methodes  proposees,  en  y  ajoutant  ses  decou- 
vertes  personnelles  sur  ces  questions  difficiles.  On  pent  caracteriser 
toutes  ces  recherches,  en  disant  qu'on  s'y  propose  de  trouver  explicite- 
ment  des  integrales  avec  le  plus  grand  degre  possible  d'indetermination. 
Quelquefois,  les  methodes  sont  des  indications  de  marche  a  suivre  quand 
telle  circonstance  heureuse  se  presente,  et  on  cherche  des  classes  d'equa- 
tions pour  lesquelles  il  en  soit  ainsi ;  dans  d'autres  cas,  on  renonce  au 
moins  temporairement  a  I'integration  complete,  et  on  recherche  des  solu- 
tions de  plus  en  plus  etendues  au  moyen  de  transformations  convenables 
comme,  par  exemple,  celles  de  M.  Bianchi  pour  I'equation  des  surfaces  a 
courbure  constante. 

Les  idees  du  grand  geometre  norvegien,  Sophus  Lie,  dont  la  science 


232  Emile  Picard: 

deplore  la  perte  recente,  ont  exerce  aussi  depuis  vingt  ans  une  grande 
influence  dans  I'etude  des  equations  differentielles  sous  le  point  de  vue 
qui  nous  occupe  en  ce  moment.  La  theorie  des  groupes  de  transforma- 
tions, une  des  plus  belles  creations  mathematiques  de  ce  siecle,  est  venue 
apporter  un  element  incomparable  de  classification  ;  elle  a  permis  de  faire 
une  vaste  synthese  en  donnant  une  origine  commune  a  des  notions  eparses 
qui  paraissaient  sans  liens. 

Je  disais  tout  a  I'heure  que  nos  classifications  se  plient  difficilement  a 
la  complexite  des  choses.  Certains  problemes  se  trouvent  a  un  confluent, 
ou  se  rencontrent  I'ancienne  Ecole  de  Monge  et  d' Ampere  et  I'Ecole  plus 
recente  qui  se  rattache  a  la  theorie  moderne  des  fonctions.  Monge  avait 
integre  I'equation  des  surfaces  minima,  et  c'est  la  un  de  ses  titres  de 
gloire.  Ses  formules  ont  ete  transformees  par  Weierstrass,  et  alors  a 
apparu  le  lien  entre  la  theorie  des  fonctions  d'une  variable  complexe  et  la 
theorie  des  surfaces  minima.  Un  probleme  appelle  vivement  I'attention 
dans  cette  theorie  :  c'est  le  probleme  de  Plateau  relatif  aux  surfaces 
minima  passant  par  un  contour  donne.  II  a  ete  resolu  seulement  dans 
des  cas  tres  speciaux ;  je  crois  qu'en  exercant  la  sagacite  des  analystes  il 
sera  quelque  jour  1' occasion  de  progres  importants  dans  I'analyse  generale. 

IV. 

J'ai  surtout  parle  jusqu'ici  des  equations  aux  derivees  partielles.  La 
theorie  des  equations  differentielles  ordinaires  est  plus  speciale,  d'autant 
que  quelques  uns  ont  une  tendance  a  la  regarder  comme  un  chapitre  de  la 
theorie  des  fonctions  analytiques.  Apres  les  remarques  que  j'ai  faites 
hier,  je  n'ai  pas  besoin  d'ajouter  que  ce  n'est  pas  la  mon  opinion ;  je  vous 
ai  indique  plusieurs  problemes  qui  ne  relevent  en  rien  de  la  theorie  des 
fonctions  analytiques,  et  il  me  suffira  de  citer  encore  I'extension  des  idees 
de  Galois  aux  equations  differentielles.  Ceci  dit,  il  n'est  pas  douteux  que 
les  progres  de  la  theorie  des  fonctions  analytiques  ont  exerce  la  plus 
heureuse  influence  sur  certains  points  de  la  theorie  des  equations  diffe- 
rentielles ordinaires.  Je  ne  ferai  que  rappeler  le  memoire  celebre  de 
Puiseux  sur  les  fonctions  algebriques,  dans  lequel  etudiant  a  un  point 
de  nouveau  les  plus  simples  des  equations  differentielles  a  savoir  les 
quadratures,  il  revele  I'origine  de  la  periodicite  des  integrales  de  differen- 
tielles algebriques.  Les  recherches  de  Briot  et  Bouquet  ne  sont  pas 
moins  classiques  ;  les  auteurs  y  etudient  les  circonstances  singulieres  qui 
peuvent  se  presenter  dans  une  equation  du  premier  ordre  quand  le  coefli- 


Seconde  Conference.  233 

cient  differentiel  devient  infini  ou  iiidetermine.  II  faiit  se  reporter  a  pres 
de  cinquante  ans  en  arriere  pour  bien  juger  ce  memoire,  ou  pour  la 
premiere  fois  est  mis  en  evidence  le  role  des  points  singuliers  dans  I'etude 
des  fonctions ;  ces  notions  nous  sont  bien  familieres  aujourd'hui,  mais 
nous  ne  devons  pas  oublier  que  ce  sont  les  memoires  de  Puiseux  et  de 
Briot  et  Bouquet  qui  en  ont  montre  la  haute  importance.  II  semble  que 
le  memoire  de  Briot  et  Bouquet  aurait  du  etre  immediatement  I'origine 
de  travaux  dans  la  meme  voie,  mais  bien  des  annees  se  passerent  avant 
qu'il  ne  fut  repris  et  complete.  C'est  en  Allemagne,  sous  I'influence  de 
I'enseignement  de  Weierstrass  que  nous  voyons  d'abord  reparaitre  I'etude 
des  singularites  des  equations  differentielles,  et  cela  pour  les  equations 
differentielles  lineaires.  II  est  vraiment  curieux  que  Briot  et  Bouquet, 
apres  avoir  traite  le  cas  plus  difficile  des  singularites  d'une  equation  non 
lineaire,  fut-elle  du  premier  ordre,  n'aient  pas  songe  a  s'occuper  des  equa- 
tions lineaires,  laissant  a  M.  Fuchs  I'honneur  de  fonder  une  theorie,  dont 
I'illustre  geometre  allemand  a  fait  lui-meme  des  applications  du  plus 
haut  interet,  et  qui  a  provoque  un  nombre  immense  de  recherches.  On 
remplirait  des  bibliotheques  avec  les  memoires  composes  depuis  trente  ans 
sur  la  theorie  des  equations  lineaires.  Je  ne  puis  songer  a  vous  parler 
des  nombreuses  classes  d'equations  dont  I'etude  a  ete  faite.  En  restant 
dans  les  generalites,  je  rappelle  seulement  que  I'etude  des  points  singuliers 
presente  une  grande  difference  suivant  que  ce  point  singulier  est  regulier, 
comme  dit  M.  Fuchs,  ou  presente  les  caracteres  d'un  point  singulier 
essentiel.  Ce  dernier  cas  est  de  beaucoup  plus  difficile ;  M.  Thome  a 
forme  des  series  satisfaisant  formellement  a  I'equation,  mais  qui  en  general 
ne  sont  pas  convergentes.  Remarquons  a  ce  propos  que  Briot  et  Bouquet 
ont  les  premiers  montre  qu'une  equation  diiferentielle  pouvait  conduire  a 
une  serie  en  general  divergente  ;  leur  exemple  bien  simple  est  I'equation 

x^-^  =  ax  +  hy 
dx 

verifiee  par  une  serie  entiere  dont  le  rayon  de  convergence  est  nul.  Cette 
petite  constatation  a  appele  I'attention  sur  un  fait  d'une  importance 
capitale,  et  qui  ne  se  rencontre  que  trop  frequemment  dans  les  applica- 
tions; les  developpements  purement  formels  sont  nombreux  en  meca- 
nique  analytique  et  mecanique  celeste,  ou  ils  font  le  desespoir  des 
geometres.  Pour  les  equations  lineaires,  ces  developpement  ont  un 
certain  interet,  comme  I'a  montre  M.   Poincare,  au  point  de  vue  de  la 


234  Emile  Picard. 

representation  asymptotique  des  integrales.  On  pent  d'ailleurs  obtenir 
et  de  bien  des  manieres,  una  representation  analytique  des  integrales 
autour  du  point  singulier.  Je  dois  enfin  mentionner,  relativement  aux 
points  singuliers  irreguliers,  les  recherches  de  M.  H.  von  Koch  qui  a  tire 
tres  heureusement  parti  dans  cette  question  des  resultats  obtenus  sur  les 
determinants  d'ordre  infini. 

Revenons  aux  equations  du  premier  ordre.     Briot  et  Bouquet  ont 
surtout  etudie  les  singularites  en  faisant  les  reductions  au  type 

ax 

ou  /  est  holomorpbe  et  s'annule  pour  a:  =  0,  1/  =  0,  et  leurs  recherches 
ont  ete  depuis  completees  par  la  connaissance  de  la  forme  analytique  des 
integrales  au  voisinage  du  point  singulier.  Le  cas  plus  complique  de 
I'equation 

^'"^  =  /(^,2/)         (^^2)  (1) 

n'avait  fait  jusqu'a  ces  derniers  temps  I'objet  d'aucune  recherche  depuis 
les  quelques  lignes  que  lui  avaient  consacrees  Briot  et  Bouquet.  Cette 
etude  vient  d'etre  reprise  simultanement  par  M.  Horn  et  par  M.  Bendix- 
son.  Ces  auteurs  se  servent  d'une  methode  convenable  d'approximations 
successives  dont  j'indiquerai  le  principe.  Nous  supposons  expressement 
que  X  reste  reel  et  se  rapproche  de  zero  par  valeurs  positives,  et  posons 

f(x,  y)  =  %  +  F(x,  y) 

F  ne  contenant  pas  de  terme  du  premier  degre  en  y  independant  de  x. 
Si  la  partie  reelle  de  b  est  positive,  I'equation  precedente  a  une  infinite 
d'integrales  tendant  vers  zero  en  meme  temps  que  x,  et  elle  n'en  a  qu'une 
quand  la  partie  reelle  de  b  est  negative.  Les  deux  cas  peuvent  etre 
traites  en  faisant  les  approximation  successives 

x-^^=by,  +  F(x,y^^ 


^  =  by,  +  F(ix,y,_{) 


Seconde  Conference.  235 

et  on  obtient  ainsi  une  representation  analytique  des  integrales  (ou  de 
I'integrale).     II  existe  un  developpement 

a-^x  +  02^2  4-  •••  +  a^x"  +  ••• 

satisfaisant  formellement  a  I'equation  (1),  mais  dont  le  rayon  de  conver- 
gence est  nul  en  general ;  c'est  la  generalisation  de  la  remarque  de  Briot 
et  Bouquet,  et  on  pent  ajouter  que  la  derivee  d'ordre  n  de  toutes  les 
integrales  considerees  tend  vers  1  •  2  •••  w  •  a„,  quand  x  tend  vers  zero. 
De  plus,  quand  il  y  a  une  infinite  d'integrales  tendant  vers  zero  en  meme 
temps,  elles  sont  toutes  representees  asymptotiquement  par  le  meme 
developpement,  ce  qui  est  evidemment  defavorable  pour  I'interet  que 
peut  presenter  une  telle  representation  asymptotique.  Les  methodes 
precedentes  sont  d'ailleurs  susceptibles  de  s'etendre  a  un  systeme  d'equa- 
tions  differentielles.  Je  ferai  encore  i;ne  remarque  importante  sur 
I'equation  (1) ;  le  cas  ou  la  partie  reelle  de  h  est  nulle  echappe  complete- 
ment  a  la  methode.  L'equation  a  en  general  des  integrales  qui  ne  ten- 
dent  vers  aucune  limite  pour  x  =  0.  On  se  trouve  alors,  sur  un  exemple 
tres  simple,  en  presence  des  difficultes  considerables  que  Ton  rencontre 
dans  plusieurs  questions  de  mecanique  analytique;  c'est  en  vain  que 
Ton  a  tente  jusqu'ici  de  proceder  par  approximations  successives  con- 
vergentes  et  les  developpements  essayes  sont  en  general  divergents. 

Quoi  qu'il  en  soit  des  difficultes  restant  encore  a  surmonter,  des 
progres  serieux  ont  ete  realises  ces  dernieres  annees  dans  I'etude  des 
integrales  des  equations  non  lineaires  au  voisinage  des  points  singuliers 
mis  en  evidence  par  la  forme  meme  de  I'equation  differentielle.  De  tels 
points  singuliers  sont  les  seuls  que  puissent  avoir  les  integrales  quand 
il  s'agit  d'une  equation  lineaire,  mais  il  en  est  autrement  pour  les  equa- 
tions non  lineaires.  En  dehors  des  points  singuliers,  qui  sont  apparents 
sur  I'equation,  il  peut  y  en  avoir  d'autres  variables  d'une  integrale  a 
I'autre.  Les  equations  du  premier  ordre  ne  presentaient  pas  a  cet  egard 
de  bien  grandes  difficultes.  En  se  bornant  aux  equations  differentielles 
algebriques,  tous  les  points  singuliers  qui  ne  sont  pas  apparents  ne 
peuvent  etre  que  des  points  critiques  algebriques.  Des  exemples  simples 
montraient  que  pour  les  equations  d'ordre  superieur  au  premier,  il  n'en 
etait  plus  de  meme  et  qu'il  pouvait  y  avoir  des  points  essentiels  mobiles; 
I'attention  avait  ete  appelee  sur  ce  point  quand  on  avait  voulu  etendre 
aux  equations  du  second  ordre  a  points  critiques  fixes  les  methodes  qui 
avaient  reussi  pour  les  equations  du  premier  ordre  possedant  la  meme 


236  Emile  Picard: 

propriete.  La  difficulte  signalee  restait  entiere,  quand  M.  Painleve  est 
venu  faire  une  importante  distinction  et  signaler  un  fait  inatteudu.  Les 
points  singuliers  mobiles  peuvent  se  partager  en  deux  classes,  les  points 
singuliers  algebriques  ou  transcendants  pour  lesquels  I'integrale  et  ses 
derivees  acquierent  une  valeur  determinee  finie  ou  infinie,  et  les  points 
singuliers  essentiels.  M.  Painleve  a  etabli  que,  dans  les  equations  diffe- 
rentielles  algebriques,  le  cas  ou  les  points  singuliers  essentiels  sont 
mobiles  est  un  cas  exceptionnel.  Ces  equations  se  trouvent  ainsi  par- 
tagees  en  deux  classes,  une  classe  generale  pour  laquelle  I'integrale 
generale  n'a  pas  de  singularites  essentielles  mobiles,  et  une  classe  singu- 
liere.  L'interet  de  cette  distinction  est  tres  grand  dans  I'etude  de 
quelques  classes  particulieres  d'equations  differentielles. 

V. 

Arretons  nous  specialement  sur  le  cas  ou  la  variable  et  les  fonctions 
restent  reelles ;  c'est  le  cas  interessant  pour  les  applications.  Nous 
designerons  par  t  la  variable  independante  qui  sera,  si  Ton  veut,  le 
temps.  Pour  etudier  quantitativement  les  fonctions  definies  par  les 
equations  differentielles,  c'est  a  dire  pour  pouvoir  evaluer  numerique- 
ment  les  valeurs  de  ces  fonctions,  on  doit  desirer  d'avoir  des  represen- 
tations de  celles-ci  permettant  de  les  calculer  pour  un  intervalle  de  temps 
aussi  grand  que  possible.  H  y  a  des  classes  assez  etendues  d'equations 
differentielles,  d'apres  la  forme  desquelles  on  est  assure  d'obtenir  des 
developpements  valables  pour  toute  valeur  de  t.  Un  cas  tres  simple 
est  celui  des  equations 
dv  • 

-^  =fi(t,   yi,  ^2'   •••'  Vn')  (*'  =  1,  2,   •••,  W). 

On   suppose   que   les  fonctions  /  restent  continues  pour  toutes   les 

valeurs  reelles  et  finies  de  t  et  des  ^,  et  que  de  plus  les  derivees  -^ 

restent  en  valeurs  absolues  moindres  qu'un  nombre  fixe.  La  metliode 
de  Cauchy  ou  la  methode  des  approximations  success! ves  donne  pour 
les  y  des  developpements  valables  pour  toute  valeur  du  temps. 

En  supposant  que  les  fonctions  /  soient  analytiques  et  regulieres 
pour  toute  valeur  reelle  finie  ou  infinie  de  t  et  des  y,  on  pent  proceder 
autrement  dans  la  recherche  d'un  developpement  valable  pour  toute 
valeur  du  temps.  II  suffit  de  faire,  avec  M.  Poincare,  une  representa- 
tion conforme,  sur  un  cercle  situe  dans  le  plan  d'une  variable  z,  d'une 


Seconde  Conference.  237 

bande   tres   petite  dans   le   plan  de  la  variable  t  (supposee   un   instant 
complexe),  bande  parallele  a  I'axe  reel,  ce  qui  revient  a  poser 


e"'  +  l 


On  pent  ici  proceder  encore  d'une  autre  maniere  en  se  rappelant  que 
M.  Painleve  a  etabli  que  toute  fonction  holomorphe  d'une  variable  reelle 
dans  un  intervalle  peut  etre  developpee  en  une  serie  de  polynomes  dont 
les  coefficients  dependent  lineairement  des  valeurs  de  la  fonction  et  de 
ses  derivees  pour  une  valeur  particuliere  t  =  t^, 

II  y  a  des  cas  ou  I'equation  ne  rentre  pas  dans  les  types  precedents, 
et  ou  Ton  sera  cependant,  au  moins  pour  certaines  integrales,  assure  de 
la  possibilite  d'un  developpement  toujours  valable.  Je  citerai  comme 
premier  exemple  les  equations 

ou  «  et  6  sont  deux  constantes  positives ;  /  et  ^  designe  des  series  holo- 
morplies  en  -,  x  et  y,  et  ne  renfermant  pas  de  termes  constants  et  de 
termes  du  premier  degre  en  x  et  y.  II  est  aise  d'etablir  que,  pour 
t=tQ  suffisamment  grand,  les  valeurs  initiales  etant  suffisamment  petites, 
les  integrales  correspondantes  tendront  vers  zero  pour  t=oo.  De  tels 
exemples  sont  malheureusement  tres  rares ;  on  peut  encore  citer  les 
problemes  de  mecanique  ou  il  y  a  une  fonction  des  forces.  Chacun  salt 
que  I'equilibre  est  stable,  dans  le  voisinage  d'une  position  ou  la  fonction 
des  forces  est  maxima,  mais  ce  resultat  classique  provient  de  I'etude 
indirecte  des  equations  differentielles  ;  le  meme  probleme  nous  montre 
vite  combien  une  etude  directs  serait  desirable,  et  combien  de  difficultes 
restent  a  vaincre.  Ainsi,  supposons  qu'il  n'y  ait  pas  de  fonction  de 
forces  et  bornons  nous  a  un  point  materiel.     Ecrivons  les  equations 

•^=ax  +  hy+...  -^=a'x  +  h'y+...  (2) 

ou  les  seconds  membres  sont  des  developpements  suivant  les  puissances 
de  x  et  y,  et  convergents  pour  x  et  y  assez  petits.  Le  point  x=-0,  y=0 
correspond-il  a  une  position  d'equilibre  stable  ?  II  est  impossible  ac- 
tuellement  de  repondre  a  cette  question.  II  y  a  peut-etre  quelques 
mecaniciens  qui  croient  que   la   nature  de  I'equilibre  depend  seulement 


238  Emile  Picard : 

des  termes  du  premier  degre  dans  le  second  membre.  Nous  nous  garde- 
rons  bien  de  leur  en  vouloir,  car  c'etait  au  fond  I'erreur  de  Lagrange, 
mais  il  est  clair  qu'en  reduisant  les  equations  a  la  partie  lineaire,  on  pent 
avoir  une  solution  stable  qui  cesse  de  I'etre  quand  on  retablit  les  termes 
d'ordre  superieur.  Les  equations  (2)  presentent  une  particularite  curi- 
euse  qui  merite  d'etre  signalee.  On  pent  se  proposer  de  trouver  une 
integrale  premiere 

F  etant  en  holomorphe  en  a:,  y,  x\  y\  et  commengant  par  des  termes  du 
second  degre.  Or  on  trouve  une  telle  fonction  F  au  point  de  vue  formel, 
mais  la  serie  ainsi  obtenue  ne  converge  pas  en  general.  J'ajoute  que, 
si  la  force  dependait  non  seulement  de  la  position  du  point  mais  de  la 
vitesse,  c'est-a-dire  si  dans  (2)  les  seconds  membres  dependaient  aussi 
de  d  et  y,  la  recherche  de  la  fonction  F  ne  pourrait  plus  generalement 
etre  effectuee,  mais  il  serait  plus  facile  de  repondre  a  la  question  relative 
a  la  stabilite. 

Quand  on  a  aucune  notion  de  la  grandeur  de  I'intervalle  pour  lequel 
les  fonctions  definies  par  les  equations  differentielles  sont  continues,  on 
pent  cependant  trouver  des  developpements  valables  pour  tout  le  temps 
pendant  lequel  les  fonctions  resteront  continues.  J'ai  dit  tout  a  I'heure 
que  Ton  pouvait  deduire  de  tels  developpements  de  la  methode  classique 
de  Cauchy  ;  c'est  la  un  resultat  interessant,  mais  malheureusement  il 
n'a  guere  qu'un  interSt  theorique,  car  il  semble  bien  difficile  de  deduire 
de  ces  developpements  quelques  renseignements  sur  le  champ  ou  les 
integrales  restent  continues. 

II  y  aura  cependant  des  cas  ou  certaines  proprietes  auxiliaires  des 
equations  permettent  d'avoir  des  renseignements  sur  le  champ  ou  les 
integrales  restent  continues.  Que  Ton  prenne,  par  exemple,  les  six 
equations  classiques  en  j9,  5-,  r,  ?/,  y\  y"  relatives  au  mouvement  d'un 
solide  pesant  suspendu  par  un  point ;  I'integrale  des  forces  vives  et 
I'integrale  ?/^  3/'^,  y"^  =  const,  permettent  de  reconnaitre  que  les  six 
fonctions  precedentes  resteront  finies  pour  toute  valeur  du  temps,  et 
nous  sommes  alors  assure  que  pour  ce  probleme  la  methode  de  Cauchy 
donne  des  developpements  valables  pour  toute  valeur  du  temps. 


Seconde  Conference.  239 

VI. 

A  I'ordre  d'idees  qui  nous  occupe,  se  rattachent  les  travaux  de  M. 
Poincare  sur  les  solutions  periodiques,  et  sur  les  solutions  asymptotiques. 
L'etude  des  solutions  periodiques  d'une  equation  differentielle  presente 
un  interet  particulier.  Je  connais  peu  d'exemples  ou  on  puisse  trouver 
directement  une  solution  periodique.  Dans  ses  travaux  sur  ce  sujet,  M. 
Poincare  procede  par  voie  indirecte  ;  il  profite  de  la  presence  d'une  con- 
stante  tres  petite  dans  les  equations,  et  il  raisonne  par  continuite  en  par- 
tant  d'une  solution  periodique  pour  la  valeur  zero  de  cette  constante.  II 
serait  a  desirer  que  Ton  put  penetrer  par  une  autre  voie  dans  l'etude  des 
solutions  periodiques.  Quant  aux  solutions  asymptotiques  a  une  seule 
solution,  leur  etude  resulte  de  developpements  analytiques  simples ;  mais 
I'existence  dans  certains  cas  particuliers  de  solutions  doublement  asymp- 
totiques, c'est  a  dire  de  solutions  asymptotiques  pour  <  =  —  qo  a  une 
solution  periodique  et  de  nouveau  asymptotiques  pour  ^  =  +  oo  a  cette 
meme  solution  etait  extremement  cachee,  et  leur  decouverte  a  demande 
un  effort  considerable. 

L'etude  des  courbes  definies  par  les  equations  differentielles  est  sur- 
tout  une  etude  qualitative.  Si  Ton  considere  d'abord  une  equation  du 
premier  ordre  et  du  premier  degre. 

r^  =  ^     (X  et  Y  polynomes  en  x  et  y)  (2) 

l'etude  des  points  singuliers  generaux  se  deduit  des  resultats  de  Briot  et 
Bouquet.  Ces  points  se  partagent  en  trois  types,  que  M.  Poincare  ap- 
pelle  des  cols,  des  nceuds  et  des  foyers.  Un  point  singulier  d'une  nature 
deja  plus  compliquee  est  fourni  par  ce  que  M.  Poincare  appelle  un  centre, 
qui  en  general  presente  de  I'analogie  avec  les  foyers  mais  autour  duquel 
dans  certains  cas  I'integrale  constitue  une  courbe  fermee.  On  a  alors  un 
exemple  de  solutions  periodiques  dont  la  periode  depend  des  conditions 
initiales.  Les  travaux  les  plus  recents  sur  les  points  singuliers  de  courbes 
integrales  de  I'equation  (2)  sont  dus  a  M.  Bendixson  ;  le  savant  geometre 
suedois  a  etabli  en  particulier  que  s'il  existe  pour  I'equation  (2)  une 
courbe  integrale  allant  a  I'origine  avec  une  tangente  determinee,  toutes 
les  courbes  integrales  allant  a  I'origine  y  parviendront  avec  des  tangentes 
determinees. 

L'etude  des  courbes  integrales  ne  doit  pas  etre  bornee  au  voisinage 
des  points  singuliers ;  on  doit  cherclier  a  se  rendre  compte  de  leur  forme 


240  Emile  Picard : 

sur  le  plan  tout  entier  ou  sur  la  sphere  en  faisant  une  perspective.  Si 
Ton  cliemine,  pour  I'equation  (2),  sur  une  courbe  integrale,  qu'arrivera- 
t-il  ?  Cette  courbe  pent  etre  fermee  de  telle  sorte  qu'on  reviendra  au 
point  de  depart ;  elle  peut  aussi  avoir  un  des  foyers  comme  point  asymp- 
tote. Elle  peut  avoir  encore  pour  courbe  asymptote  une  courbe  fermee 
satisfaisant  d'ailleurs  a  I'equation  differentielle.  Ces  courbes  fermees,  que 
M.  Poincare  appelle  cycles  limites  jouent  un  role  capital,  et  c'est  dans  les 
cas  ou  il  est  possible  de  se  rendre  compte  de  leur  position  que  la  dis- 
cussion de  I'equation  peut  etre  faite  d'une  maniere  complete. 

Pour  les  equations  du  premier  ordre  mais  de  degre  superieur  les  dif- 
ficultes  sont  beaucoup  plus  grandes.  L'etude  des  points  singuliers  ge- 
neraux  a  ete  faite ;  elle  trouve  en  particulier  son  application  dans  des 
problemes  comme  celui  des  lignes  de  courbure  d'une  surface  passant  par 
un  ombilic.  L'etude  des  courbes  dans  tout  le  plan  est  singulierement 
compliquee  par  un  fait  qui  ne  pouvait  se  rencontrer  pour  les  equations 
du  premier  degre.  II  peut  arriver  qu'une  courbe  integrale  couvre  une 
aire,  c'est  a  dire  puisse  se  rapprocher  autant  qu'on  voudra  d'un  point 
arbitraire  dans  une  aire. 

D'apres  les  difficultes  que  presentent  encore  les  equations  du  premier 
ordre,  il  est  clair  que  pour  les  equations  d'ordre  superieur  au  premier 
l'etude  qualitative  des  integrales  sollicitera  longtemps  encore  I'effort  des 
chercheurs.  Au  point  de  vue  analytique,  une  circonstance  importante  est 
a  noter.  Tandis  que  pour  le  premier  ordre,  on  peut  tirer  parti  dans  quel- 
ques  cas  comme  celui  des  centres  de  certains  developpements  en  serie,  il 
arrive  au  contraire  ici  dans  les  cas  correspondants  que  les  developpements 
analogues  sont  purement  f ormels ;  nous  en  avons  vu  un  exemple  en  par- 
lant  tout  a  I'heure  de  la  stabilite  de  I'equilibre.  Remarquons  a  ce  propos 
que  les  questions  d'instabilite  sont  beaucoup  plus  faciles  a  traiter  que  les 
questions  de  stabilite  comme  il  resulte  des  interessantes  recherches  de  M. 
Liapounoff.  Quand  il  y  a  une  fonction  des  forces  I'equilibre  est  stable 
si,  pour  cette  position,  la  fonction  des  forces  est  maxima.  Quant  aux 
positions  d'equilibre  pour  lesquelles  cette  derniere  condition  n'est  pas 
remplie,  on  les  a  toujours  regardees  comme  instables,  mais  leur  instabilite 
n'avait  pas  ete  demontree.  M.  Liapounoff  I'a  etablie  en  particulier  pour 
le  cas  que  I'on  peut  appeler  general  ou  la  non  existence  du  maximum  de 
la  fonction  des  forces  se  reconnait  par  les  termes  du  second  ordre. 

Je  citerai  seulement  un  exemple  relatif  aux  courbes  integrales  d'une 
equation  d'ordre  superieur  au  premier.      Dans  un  memoire  recent,  M. 


Troisieme  Conference.  241 

Hadamard  vient  d'etudier  les  lignes  geodesiques  des  surfaces  a  courbures 
opposees  et  a  connexion  multiple  ayant  un  nombre  limite  de  nappes  in- 
finies.  II  etablit  que  les  tangentes  aux  lignes  geodesiques  passant  par  un 
point  de  la  surface,  et  restant  a  distance  finie,  forment  un  ensemble  par- 
fait  non  continu.  Ce  resultat  est  interessant  au  point  de  vue  de  la  dispo- 
sition des  lignes  geodesiques  de  la  surface ;  il  montre  qu'il  existe  des 
lignes  geodesiques  se  rapprochant  d'une  geodesique  fermee  determinee, 
puis  abandonnant  celle-ci  pour  se  rapprocher  d'une  autre,  puis  passant  a 
une  troisieme,  et  ainsi  de  suite  indefiniment.  II  montre  de  plus  que 
Failure  des  courbes  integrales  pent  dependre  dans  certains  cas,  des  pro- 
prietes  discontinues  je  veux  dire  arithmetiques  des  constantes  d'integra- 
tion.  C'est  sur  cette  idee  que  je  veux  m'arreter ;  dans  la  theorie  des 
equations  differentielles  comme  en  maintes  parties  des  mathematiques,  les 
recherches  sont  obligees  de  prendre  un  caractere  arithmetique.  C'est 
V arithmStisation  des  matliematiques  dont  parlait  M.  Klein  dans  un  article 
recent. 

J'ai  essaye,  messieurs,  en  restant  dans  les  generalites  et  sans  prendre 
aucune  classe  particuliere  d'equations,  de  faire  une  sorte  de  carte  geogra- 
phique  sommaire  de  la  theorie  des  equations  differentielles.  Beaucoup 
de  voies  sont  ouvertes  et  dans  des  directions  tres  varices ;  sur  plus  d'un 
point,  les  questions  sont  seulement  posees,  mais  elles  paraissent  bien 
posees  ;  et  nous  nous  rendons  compte,  ce  qui  a  son  prix,  de  la  nature  des 
difficultes  qu'il  faudra  vaincre.  C'est  une  etroite  alliance  entre  les  dis- 
ciplines les  plus  diverses  qui  amenera  maintenant  de  nouveaux  progres. 
II  n'est  plus  permis  aujourd'hui  au  geometre  inventeur  d'etre  I'homme 
d'un  seul  point  de  vue,  et  il  faut  nous  resigner  a  de  grandes  complica- 
tions. C'est  un  privilege  que  les  sciences  matliematiques  partageront 
probablement  dans  I'avenir  avec  d'autres  sciences.  Esperons  seulement 
que  des  hommes  de  genie  viendront,  de  loin  en  loin,  donner  au  moins  pour 
un  temps  I'illusion  de  la  simplicite. 

Troisieme  Conference. 

Sur  la  Theorie  des  Fonctions  Analitiques  et  sur  quelques  Fonctions  Speciales. 

La  theorie  des  fonctions  de  variables  complexes  est  de  venue  aujourd'hui 
une  branche  considerable  de  I'analyse  mathematique.  EUe  doit  son  bril- 
lant  essor  a  la  decouverte  de  quelques  propositions  generales  parmi  les- 
quelles  se  trouvent  au  premier  rang  les  theoremes  de  Cauchy  sur  les 


242  Emile  Picard: 

integrales  prises  le  long  d'un  contour.  Ces  lois  generales  des  fonctions 
analytiques  appliquees  a  des  fonctions  speciales  donnent  souvent  avec 
facilite  leurs  principales  proprietes.  L'application  de  ces  lois  constitue 
une  methode  syntlietique,  et  des  resultats  auxquels  avaient  conduit  une 
longue  serie  de  transformations  de  calculs  apparaissent  quelquefois  avec 
une  evidence  intuitive.  La  theorie  des  fonctions  elliptiques  en  offre  un 
memorable  exemple,  et  n'y  a-t-il  pas  quelque  chose  de  merveilleux  a 
integrer  avec  M.  Hermite  le  long  d'un  parallelogramme  de  periodes 
et  a  obtenir  ainsi  d'un  trait  de  plume  les  principales  proprietes  des 
fonctions  doublement  periodiques  ?  La  fagon  dont  Riemann  pose  et 
resout  dans  sa  dissertation  inaugurale  le  probleme  des  integrales  abe- 
liennes  n'est  pas  moins  digne  d'etre  meditee  comme  exemple  d'une 
methode  synthetique  dans  la  theorie  des  fonctions. 

I. 

II  n'est  plus  douteux  aujourd'hui  que  les  principes  essentiels  qui  sont 
a  la  base  de  la  theorie  n'aient  ete  connus  de  Gauss.  On  sait  que  celui-ci 
ne  publia  pas  ses  recherches  sur  ce  sujet.  On  ne  pent  guere  admettre 
qu'il  n'en  ait  pas  saisi  la  haute  importance ;  fidele  a  sa  devise  "  pauca  sed 
matura  "  il  attendait  sans  doute  de  s'etre  livre  a  une  plus  longue  elabora- 
tion, quand  Cauchy  fit  connaitre  ses  decouvertes.  On  doit  done  regarder 
Cauchy  comme  le  veritable  fondateur  de  la  theorie  appelee  a  un  si  grand 
avenir ;  non  pas  certes  qu'il  I'ait  presentee  sous  une  forme  didactique. 
Ouvrant  des  voies  nouvelles,  son  esprit  toujours  en  travail  se  souciait  peu 
de  donner  a  ses  conceptions  une  forme  parfaite.  On  suit  le  travail 
d'invention  dans  maintes  publications  de  Cauchy,  notamment  quand  on 
parcourt  dans  ses  GEnvres  Completes  les  notes  innombrables  extraites  des 
Comptes-Rendus.  Dans  la  theorie  qui  nous  occupe,  une  place  a  part  doit 
etre  faite  a  I'idee  fondamentale  d'etendre  la  notion  de  I'integrale  definie 
en  faisant  passer  la  variable  par  une  succession  de  valeurs  imaginaires  ; 
cette  conception  a  ete  la  source  des  plus  belles  decouvertes,  et  la  represen- 
tation d'une  fonction  par  une  integrale  le  long  d'un  contour  ferme  gardera 
a  jamais  le  nom  d'integrale  de  Cauchy. 

Le  point  de  depart  de  Riemann  se  rapproche  beaucoup  de  celui  de 
Cauchy  ;  il  est  tres  philosophique  de  prendre  comme  base  les  deux  equa- 
tions simultanees 

du  _dv     du  _      dv 
dx      dy     dy  dx 


Troisieme  Conference.  243 

et  de  reduire  ainsi  la  theorie  des  fonctions  d'une  variable  complexe  a 
I'etude  de  ces  deux  equations  simultanees  aux  derivees  partielles.  En 
meme  temps  apparaissent  les  liens  entre  cette  etude  et  plusieurs  questions 
de  physique  mathematique  comme  le  mouvement  permanent  des  fluides 
sur  un  plan  et  celui  de  relectricite  sur  une  plaque  conductrice ;  et  tous 
ces  problemes  sont  susceptibles  d'etre  generalises  si  au  plan  simple  dans 
lequel  se  meut  la  variable  (x,  y)  on  substitue  le  plan  multiple  de  Riemann. 
Les  deux  relations  ecrites  plus  haut  amenent  a  considerer  I'equation  Aw=  0, 
equation  qui  contient  toute  la  theorie  des  fonctions  d'une  variable  com- 
plexe, et  parmi  les  problemes  qu'on  pent  se  poser  sur  cette  equation  le 
plus  celebre  est  celui  de  la  determination  d'une  integrale  par  ses  valeurs 
sur  un  contour  ferme.  Une  application  d'une  autre  nature  concerne  la 
geometric  ;  je  veux  parler  du  probleme  des  cartes  geographiques  qui  amene 
a  la  question  de  la  representation  conforme  d'une  aire  sur  une  autre. 

Weierstrass  a  edifie  la  theorie  des  fonctions  de  variables  complexes  sur 
une  autre  base  que  Cauchy  et  Riemann,  en  partant  des  developpements  en 
series  entieres  ;  en  France,  ces  developpements  avaient  ete  aussi  envisages 
par  M.  Meray  qui  n'avait  pas  connaissance  des  legons  de  Weierstrass. 
Le  memoire  public  en  1876  par  I'illustre  analyste  de  Berlin,  qui  a  fait 
connaitre  a  un  public  plus  etendu  les  resultats  developpes  depuis  long- 
temps  dans  I'enseignement  du  maitre,  a  ete  le  point  de  depart  d'un  grand 
nombre  de  travaux  sur  la  theorie  des  fonctions.  Cauchy  avait  deja  obtenu 
d'importants  resultats  sur  le  developpement  en  sommes  ou  en  produits 
infinis  de  certaines  categories  de  fonctions.  II  etait  reserve  a  Weierstrass 
et  a  ses  disciples  de  traiter  ces  questions  dans  toute  leur  generalite.  La 
decomposition  des  fonctions  entieres,  c'est  a  dire  des  fonctions  uniformes 
et  continues  dans  tout  le  plan,  en  facteurs  primaires  est  un  des  plus 
admirables  theoremes  de  I'analyse  moderne ;  chacun  de  facteurs  primaires 
est  le  produit  d'un  facteur  lineaire  par  une  exponentielle.  Les  developpe- 
ments des  fonctions  uniformes  en  sommes  et  en  produits  infinis  ont  fait 
ensuite  I'objet  d'un  grand  nombre  de  travaux  parmi  les  quels  il  faut  citer 
tout  particulierement  le  memoire  de  Mittag-Leffler  qui  a  aborde  ces  prob- 
lemes avec  la  plus  grande  generalite  possible.  Je  rappellerai  aussi  un 
memoire  de  M.  Runge  auquel  des  recherches  toutes  recentes  viennent  de 
redonner  de  I'actualite,  ou  se  trouve  en  particulier  etabli  que  toute 
fonction  holomorphe  dans  un  domaine  connexe  pent  dans  ce  domaine 
etre  developpee  en  une  serie  de  polynomes. 

Cauchy  et  ses  disciples  frangais,  en  etudiant  la  theorie  des  fonctions 


244  Emile  Picard: 

uniformes,  n'avaient  pas  penetre  dans  I'etude  de  ces  points  singuliers 

appeles  aujourd'hui  points  singuliers  essentiels,  dont  le  point  z=  Q  pour 
1 

la  fonction  e'  donne  I'exemple  le  plus  simple.  La  consideration  des 
facteurs  primaires  permit  a  Weierstrass  de  montrer  que  dans  le  voisinage 
d\in  point  essentiel  isole  une  fonction  uniforme  pent  se  mettre  sous  la 
forme  d'un  quotient  de  deux  fonctions  uniformes  n'ayant  pas  de  poles 
dans  le  voisinage  de  a  ;  Weierstrass  montra  aussi  que  dans  le  voisinage 
d'un  tel  point  la  fonction  s'approclie  autant  que  Ton  veut  de  toute  valeur 
donnee.  On  a  plus  tard  complete  ce  resultat,  en  etablissant  que  dans  le 
voisinage  d'un  point  singulier  essentiel  isole  la  fonction  prend  rigoureuse- 
ment  une  infinite  de  fois  toute  valeur  donnee,  une  exception  seulement 
etant  possible  pour  deux  valeurs  particulieres  au  plus.  La  demonstra- 
tion de  ce  theoreme  se  deduit  de  la  consideration  d'une  fonction  pre- 
sentant  precisement  la  propriete  qu'on  veut  demontrer  etre  impossible  ; 
cette  fonction  est  la  fonction  modulaire  de  la  theorie  des  fonctions 
elliptiques,  mais  ses  points  singuliers  ne  sont  pas  isoles.  Un  corollaire 
du  theoreme  indique  conduit  a  la  proposition  suivante  relative  aux  fonc- 
tions entieres :  si,  pour  une  fonction  entiere  G-iz)  il  existe  deux  valeurs 
a  Qt  h  telles  que  les  deux  equations  G-(z)  =  a  et  G-(z)  =  h  aient  seulement 
un  nombre  limite  de  racines,  la  fonction  G-(z)  est  un  polynome. 

De  nombreuses  tentatives  ont  ete  faites  pour  demontrer  directement 
les  theoremes  precedents  sans  recourir  a  la  theorie  des  fonctions  ellip- 
tiques.    Pour  le  theoreme  sur  les  fonctions  entieres,  M.  Hadamard  avait 

reussi  a  I'etablir  quand,  la  fonction  entiere  etant  representee  par  ^  «ot^"S 

on  a  (a„)  <  — — — ,  a  etant  positif .     Plus  recemment  M.  Borel  est 

arrive  a  le  demontrer  pour  toutes  les  fonctions  entieres  et  meme  a  le 
generaliser  considerablement. 

Les  travaux  de  M.  Hadamard  et  de  M.  Borel  publics  dans  ces 
dernieres  annees  sont  extremement  remarquables.  Dans  ces  recherches, 
une  notion  importante  introduite  par  Laguerre,  celle  du  genre  d'une 
fonction  entiere,  joue  un  role  capital  ;  ce  qui  fait  I'iuteret  de  cette 
notion,  c'est  qu'elle  est  intimement  liee  a  la  distribution  des  racines 
de  la  fonction.  M.  Poincare  avait  fait  le  premier  la  remarque  que 
le  genre  d'une  fonction  entiere  est  en  relation  etroite  avec  I'ordre  de 
grandeur  de  la  fonction  pour  les  grandes  valeurs  de  la  variable.  M. 
Hadamard  a  cherche   une   limite  du  genre  a  I'aide  des  coefficients  du 


Troisieme  Conference,  245 

developpement,  et  il  a  ^tabli  que  si  le  coefficient  de  x"^  est  moindre  que 

J-,  la  f onction  est  de  genre  E  en  designant  par  E  +1  I'entier 

(1  .  2  •••  my 

immediatement  superieur  k  \.     II   a  reussi  aussi  a  demontrer  que,  en 

designant  par  <^(w)  une  fonction  croissant  indefiniment  avec  m,  si  le 

coefficient  a^  decroit  plus  vite  que la.  p^"^^  racine  a  un  module 

[</>(w)]"' 

superieur  a  (1  —  €}(j>(p}  ou  e  est  infiniment  petit  pour  p  =  ao  .  De  ses 
resultats,  M.  Hadamard  a  fait  une  belle  application  a  I'etude  de  la  distri- 
bution des  racines  d'une  fonction  celebre  consideree  par  Riemann  dans  son 
memoire  sur  les  nombres  premiers. 

Dans  son  travail  sur  les  zeros  des  fonctions  entieres,  M.  Borel  a  eu 
surtout  pour  objet  la  demonstration  de  I'impossibilite  de  certaines  iden- 
tites.  Soit  yu,(r)  une  fonction  positive  croissant  indefiniment  avec  r. 
Designons  par  (x,(3)  une  fonction  entiere  dont  le  module  maximum  pour 
(z)  =  r  est  inferieur  a  e'^^^\  et  Hi(z)  une  fonction  entiere  dont  le  module 
maximum  est  superieur  a  [/a(0]^^"'  ^  etant  positif ;  I'identite 

ne  peut  avoir  lieu  que  si  tous  les  Gr  sont  identiquement  nuls.  En  particu- 
lier  pour  w  =  2,  une  pareille  identite  ne  peut  exister,  (tq  etant  une 
constante,  (r^  et  G-^  des  polynomes  :  c'est  le  theoreme  enonce  plus  baut  sur 
les  fonctions  entieres. 

Apres  ces  resultats  sur  les  fonctions  bolomorphes  dans  tout  le  plan, 
revenons  aux  series  entieres  dont  le  rayon  de  convergence  est  fini.  Une 
telle  serie  donne,  pour  employer  le  langage  de  Weierstrass,  un  element  de 
fonction,  en  supposant  bien  entendu  que  le  rayon  de  convergence  n'est 
pas  nul.  L'extension  analytique  d'un  tel  element  joue  un  role  capital 
dans  la  theorie  de  Weierstrass ;  il  est  dans  cette  etude  du  plus  haut 
interet  d'avoir  des  renseignements  sur  les  singularites  de  la  fonction  sur 
le  cercle  de  convergence.  Le  memoire  de  M.  Darboux  sur  I'approxima- 
tion  des  fonctions  de  tres  grand  nombres,  les  recherches  plus  recentes  de 
M.  Hadamard,  de  M.  Borel  et  de  M.  Fabry  ont  conduit  a  des  resultats 
d'un  haut  interet.  Je  ne  veux  signaler  qu'une  consequence  curieuse, 
entrevue  deja  par  M.  Pringslieim  :  c'est  qu'une  serie  entiere  a  en  general 
son  cercle  de  convergence  comme  coupure.  On  salt  que  Weierstrass  a  le 
premier  indique  un  exemple  d'un  serie  entiere  ne  pouvant  etre  prolongee 
analytiquement  an  dela   de   son  cercle   de  convergence,  et  cet  exemple 


246  Bhnile  Ficard  : 

detourne  provenait  de  la  theorie  des  fonctions  elliptiques.  II  est  vrai- 
ment  singulier  que  Ton  ait  eu  autrefois  quelques  difficultes  pour  trouver 
des  exemples  de  ce  que  Ton  doit  considerer  maintenant  comme  la  circon- 
stance  la  plus  frequente. 

Parmi  les  methodes  proposees  pour  I'etude  de  la  serie  prolongee  au 
delii  de  son  cercle  de  convergence,  il  en  est  deux  qui  sont  particuliere- 
ment  simples.  La  premiere,  employee  par  M.  E.  Lindeloff  repose  sur  la 
theorie  de  la  representation  conforme ;  la  seconde  utilise  la  notion  de 
serie  divergente  sommable  resultant  des  travaux  de  M.  Borel.  Cette 
notion  semble  devoir  jouer  dans  plusieurs  questions  d'analyse  un  role 
important.  J'en  indiquerai  en  deux  mots  le  principe.  Soit  une  serie, 
Mq  +  Mj  +  •••  w„  +  ••• ;  on  lui  associe  la  fonction  de  a: 

L'expression 

s  =  Cu(a)e^da 

pent  avoir  un  sens  quand  la  serie  initiale  est  divergente ;  on  la  regarde 
alors  comme  la  limite  de  la  serie.  En  appliquant  cette  notion  a  la  pro- 
gression geometrique  qui  represente •,  et  en  se  servant  de  I'integrale 

de  Cauchy,  on  est  alors  conduit  a  une  expression  analytique  qui  dans  bien 
des  cas  represente  la  fonction  dans  une  aire  exterieure  au  cercle  de  con- 
vergence. 

Je  ne  puis  songer  a  rappeler,  ne  fut-ce  que  d'un  mot,  les  etudes  les  plus 
importantes  faites  tout  recemment  sur  le  prolongement  analytique.  Arre- 
tons  nous  seulement  sur  un  resultat  que  vient  de  publier  M.  Mittag-Leffler. 
Considerons,  avec  I'eminent  geometre  suedois,  un  element  de  fonction  dans 
son  cercle  de  convergence,  et  sur  chaque  rayon  suivons  la  fonction 
jusqu'a  ce  que  nous  rencontrions  un  point  singulier,  celui-ci  pouvant 
d'ailleurs  etre  a  I'infini.  On  ne  garde  sur  chaque  rayon  que  la  portion 
comprise  entre  le  centre  et  le  premier  point  singulier,  et  on  obtient  ainsi 
une  aire  que  M.  Mittag-Leffler  appelle  Vetoile  correspondant  a  I'element 
de  fonction.  II  montre  qu'on  pent  obtenir  une  representation  de  la  fonc- 
tion dans  toute  I'etoile,  sous  la  forme  d'une  serie  ayant  pour  termes  des 
polynomes  en  x  dont  les  coefficients  sont  lineaires  par  rapport  aux  coeffi- 
cients du  developpement  initial ;  de  cette  faQon,  quand  on  a  en  un  point 
la  valeur  d'une  fonction  analytique  et  de  toutes  ses  derivees,  on  pent 


Troisieme  Conference.  247 

obtenir  a  I'aide  de  ces  seules  donnees  une  representation  de  la  fonction 
valable  dans  toute  une  etoile.  Ce  resultat  pourra  peut-etre  avoir  un  cer- 
tain interet  pour  la  tlieorie  des  equations  differentielles ;  il  faut  toutefois 
observer  que  dans  ce  cas  la  methode  de  Cauchy,  comme  nous  I'avons  dit 
hier,  conduit  au  meme  resultat.  Ainsi  les  series  considerees  bier  (page 
18),  constituent  des  developpements  valables  dans  une  etoile. 

Nous  avons,  dans  ce  qui  precede,  considere  un  element  de  fonction,  c'est 
a  dire  que  la  serie  ,  ,         ,         m  ,  r^\ 

avait  un  rayon  de  convergence  different  de  zero.  Si  la  serie  precedente 
ne  converge  que  pour  a;  =  0,  elle  ne  represente  rien  et  il  semble  qu'il  n'y 
ait  aucun  probleme  a  se  poser  a  son  sujet.  Cependant  nous  avons  donne 
hier  des  exemples  d'equations  differentielles  conduisant  a  de  tels  developpe- 
ments; la  derivee  d'un  ordre  quelconque  m  de  certaines  integrales  dans 
un  certain  angle  ayant  I'origine  pour  sommet  tend  vers  1  •  2  •••m  •  a,„  quand 
X  tend  vers  zero  a  I'interieur  de  Tangle  convenable  A.  Ces  conditions  re- 
latives aux  valeurs  des  derivees  ne  peuvent  manifestement  determiner  une 
seule  fonction  dans  Tangle  A  pres  de  I'origine,  car  on  pent  a  une  pre- 
miere fonction  aj outer  une  exponentielle  de  la  forme  e~^  (a  etant  convena- 
blement  cboisie)  dont  toutes  les  derivees  sont  nulles  a  I'origine  ;  mais,  en 
appliquant  sa  metbode  de  sommation  des  series  divergentes,  M.  Borel  est 
conduit  a  imposer  une  condition  supplementaire  et  a  obtenir  alors,  dans  des 
cas  etendus,  une  fonction  unique  determinee  par  la  serie  divergente  (1). 

n. 

Les  divers  travaux  que  je  viens  de  rappeler  montrent  avec  quelle 
activite  les  analystes  se  sont  occupes  dans  ces  derniers  temps  des  gene- 
ralites  concernant  les  fonctions  analytiques  d'une  variable.  La  tbeorie 
generale  des  fonctions  de  plusieurs  variables  avance  beaucoup  moins 
rapidement ;  les  questions  qui  se  posent  ici  sont  beaucoup  plus  difficiles, 
tant  en  elles-memes  que  par  le  defaut  d'une  representation  qui  fasse 
image.  Nous  suivons  une  variable  complexe  sur  son  plan,  mais  avec 
deux  variables  complexes  nous  nous  trouvons  dans  un  espace  a  quatre 
dimensions,  ou  de  plus  les  diverses  coordonnees  ne  se  presentent  pas 
symetriquement.  Au  lieu  de  deux  equations,  nous  avons  quatre  equa- 
tions aux  derives  partielles  auxquelles  doivent  satisfaire  deux  fonctions 
de  quatre  variables.  L'elimination  d'une  des  fonctions  conduit  pour 
Tautre  a  un  systeme  de  quatre  equations   aux   derivees   partielles   qui 


248  Emile  Picard : 

remplace  I'equation  de  Laplace,  mais  qui  n'a  pas  ete  etudie  directement 
comme  cette  derniere  equation.  II  semble  qu'on  ne  puisse  pour  ce  sys- 
teme  se  poser  aucun  probleme  analogue  a  celui  de  Dirichlet  et  de  Rie- 
mann  ;  nous  ne  trouvons  ici  aucune  analogie  entre  le  cas  d'une  variable 
et  celui  de  deux  variables. 

A  un  autre  point  de  vue,  le  developpement  de  Taylor  a  deux  variables 
pent  bien  servir  a  definir  un  element  de  fonction,  mais  nous  n'avons  rien 
d'analogue  au  cercle  de  convergence.  Que  sont  les  regions  de  conver- 
gence pour  un  tel  developpement?  II  faudrait  considerer  des  surfaces 
dans  I'hyperespace  a  quatre  dimensions  ;  aucune  regie  n'etant  connue 
a  cet  egard,  on  se  borne  a  considerer  deux  cercles  assez  petits  dans  les 
plans  respectifs  des  deux  variables,  cercles  a  Finterieur  desquels  la  serie 
est  convergente. 

Les  theoremes  generaux  sur  les  fonctions  analytiques  de  deux 
variables  complexes  sont  peu  nombreux.  Une  remarque  souvent  utile 
a  ete  faite  il  y  a  longtemps  par  Weierstrass  ;  elle  a  en  quelque  sorte 
pour  objet  de  mettre  en  evidence,  dans  une  fonction  de  n  variables 
holomorphes  autour  de  2:^  =  0,  ••.,  a;„=  0,  et  s'annulant  pour  ces  valeurs 
des  variables,  la  partie  de  la  fonction  qui  s'annule.  Weierstrass  montre 
que  autour  de  a^^  =  •••  =  2:„  =  0  la  fonction  peut  se  mettre  sous  la  forme 
d'un  produit  de  deux  facteurs  holomorphes,  dont  Fun  ne  s'annule  pas 
a  Forigine  et  dont  Fautre  est  un  polynome  par  rapport  a  Fune  des 
variables.  Une  autre  proposition  d'une  demonstration  delicate  est  due 
a  M.  Poincare  et  a  pour  objet  de  generaliser  le  theoreme  de  Weierstrass 
relatif  aux  fonctions  uniformes  d'une  variable  n'ayant  a  distance  finie 
que  des  poles,  fonctions  qui  peuvent  se  mettre  sous  la  forme  d'un  quotient 
de  deux  fonctions  entieres.  Pareillement  une  fonction  de  deux  variables 
qui,  pour  toutes  les  valeurs  finies  des  variables  presente  le  caractere  d'une 
fonction  rationnelle  peut  etre  mise  sous  la  forme  d'un  quotient  de  deux  fonc- 
tions entieres.  Ce  beau  theoreme  a  ete  etendu  par  M.  Cousin,  qui  a  suivi 
une  toute  autre  voie,  aux  fonctions  d'un  nombre  quelconque  de  variables. 

On  doit  encore  a  M.  Poincare  un  resultat  bien  saillant  :  je  veux 
parler  de  Fextension  aux  integrales  doubles  du  theoreme  fondamental 
de  Cauchy  relatif  aux  integrales  simples  prises  le  long  d'un  contour.  II 
n'y  a  pas  de  difficulte  a  definir  une  integrale  double  d'une  fonction 
F(x^  y)  de  deux  variables  complexes  x  Qt  y 


ff^C^^  y)^^^y 


Troisieme  Conference.  249 

sur  un  continuum  a  deux  dimensions  situe  dans  I'hyperespace  a  quatre 
dimensions  qui  correspond  aux  deux  variables  complexes.  Si  le  con- 
tinuum est  ferme,  et  qu'on  puisse  le  reduire  a  une  ligne  oii  a  un  point 
sans  que  I'  cesse  d'etre  continue,  I'integrale  sera  nulle.  Ce  resultat 
conduit  a  poser  un  grand  nombre  de  questions.  Si  F  est  une  fonction 
rationelle,  il  y  a  lieu  de  considerer  les  residus  de  I'integrale  double  ;  ces 
residus  s'expriment  par  des  periodes  d'integrales  abeliennes  ordinaires. 
Si  F  est  une  fonction  algebrique  de  x  et  3/,  on  aura  a  envisager  les 
pSriodes  de  I'integrale  double,  et  on  voit  s'ouvrir  un  vaste  champ  de 
recherches.  On  s'apergoit  d'ailleurs  bien  vite  que  si  certaines  analogies 
subsistent  avec  le  cas  d'une  variable,  il  en  est  beaucoup  d'autres  qui 
disparaissent  entierement.  Des  integrales  le  long  d'un  contour  out 
donne  a  Cauchy  le  nombre  des  racines  d'une  equation  contenues  dans 
ce  contour,  mais  dans  la  question  correspondante  du  nombre  des  racines 
communes  a  deux  equations  simultanees,  les  integrales  doubles  n'ont 
aucun  role  a  jouer  ;  ce  sont  des  integrales  triples  etendues  a  un  certain 
continuum  a  trois  dimensions  qui  interviennent  dans  cette  recherche. 

Je  parlais  tout  a  I'heure  de  la  dissymetrie  qui  se  presente  au  point 
de  vue  reel  dans  la  theorie  des  fonctions  de  deux  variables  complexes. 
II  etait  interessant  de  rechercher  si  il  n'est  pas  possible  de  generaliser 
les  deux  equations  aux  derivees  partielles  de  la  theorie  d'une  fonction 
d'une  variable.  Le  probleme  est  evidemment  indetermine  ;  tout  depend 
de  la  propriete  de  ces  equations  sur  laquelle  on  porte  specialement  son 
attention.  On  pent  se  placer  au  point  de  vue  suivant :  rechercher  tons 
les  systemes  d'equations  aux  derivees  partielles  relatifs  a  n  fonctions  de 
n  variables  independantes  et  telles  que,  si  Up  u^,  '"Un  6t  v^  v^,  •••v„  de- 
signent  deux  solutions  quelconques,  les  v  considerees  comme  fonctions 
des  u  satisfassent  au  meme  systeme.     Cette  propriete  appartient  evidem- 

,  '  ,•  du        dv     du  dv  r  111 

ment  aux  deux  equations  ■r-=T— ?  7- =  —  t-«      -Lia  recherche  de  ces  sys- 

ox      oy   oy  ax 

temes  pent  se  faire  d'une  maniere  reguliere,  et  pent  se  deduire  de  la 

connaissance  des  certains   groupes  d'ordre  fini ;    ainsi  tons  les  systemes 

du  type  precedent  d'equations  aux  derivees  partielles  du  premier  ordre 

pourront  etre  obtenus  a  I'aide  des  groupes  lineaires  et  homogenes  a  n 

variables.     II  est  possible  que,  parmi   tous    ces  systemes,  il  en  est  qui 

presentent  quelque  interet  particulier,  et  avec  lesquels  on  puisse  edifier 

une  theorie  plus  ou  moins  analogue  a  la  theorie  d'une  fonction  d'une 

variable  complexe.     Le  cas  de  w  =  3  ne  donne  rien  d'interessant  ;  pour 


250  Emile  Picard : 

w  =  4,  on  pourrait  prendre  d'abord  le  groupe  lineaire  qui  donne  naissance 
aux  quaternions,  il  lui  correspond  un  systeme  d'equations  differentielles 
qui  presente  peut-etre  quelque  interet. 

Cette  extension  de  la  theorie  des  fonctions  d'une  variable  complexe 
n'est  pas  la  seule  qui  ait  ete  proposee.  M.  Volterra  a  cherche  dans  une 
autre  voie  en  considerant  des  fonctions  de  ligne,  ce  qui  I'a  conduit  a 
d'interessantes  relations  differentielles  et  a  quelques  problemes  analogues 
a  ceux  de  Dirichlet.  L'avenir  dira  si  ces  extensions  sont  simplement  des 
curiosites  ou  si  elles  presentent  quelque  interet  general. 

III. 

Quittons  maintenant  les  generalites  et  jetons  un  coup  d'oeil  sur 
quelques  fonctions  speciales.  II  n'en  est  pas  qui  aient  ete  plus  etudiees 
que  les  fonctions  algebriques  d'une  variable ;  c'est  en  faisant  leur  etude 
que  Puiseux,  dans  un  niemoire  reste  celebre,  a  appele  I'attention  sur 
I'interet  que  presentait  la  consideration  de  la  variable  complexe.  On 
a  quelque  peine  a  se  representer  qu'il  a  paru  merveilleux  que  Vi  et  —  Vi 
puissent  etre  considerees  comme  deux  determinations  d'une  meme  fonc- 
tion ;  c'est  dans  ce  memoire  aussi  qu'apparait  pour  la  premiere  fois 
I'origine  de  la  periodicite. 

La  theorie  des  fonctions  algebriques  est  devenue  un  confluent  ou  se 
rencontrent  les  notions  les  plus  diverses ;  chacun,  suivant  ses  gouts,  pent 
y  trouver  les  points  de  vue  qu'il  prefere.  Avec  les  metliodes  de  Weier- 
strass,  nous  trouvons  la  precision  extreme  qui  caracterise  son  ecole,  et  le 
souci  constant  de  n'introduire  aucune  consideration  etrangere  a  la  theorie 
des  fonctions  fut  ce  au  prix  de  detours  longs  et  penibles.  Celui  qui  aime 
le  langage  et  les  formes  de  raisonnement  de  la  geometrie  analytique 
suivra  Brill  et  Noether  dans  leur  theorie  si  feconde  des  groupes  de 
points.  Ceux  enfin  qui  recherchent  les  grands  horizons  auront  plaisir 
a  lire  Riemann  qui,  avec  la  merveilleuse  conception  de  la  surface  qui  porte 
son  nom,  rend,  pour  ainsi  dire,  intuitifs  les  points  les  plus  delicats  de  la 
theorie.  Ce  serait  d'ailleurs  une  vue  etroite  que  de  regarder  seulement 
la  belle  conception  de  Riemann  comme  une  methode  simplicative.  Pour 
Riemann,  le  point  essentiel  est  dans  la  conception  a  priori  de  la  surface 
connexe,  formee  d'un  nombre  limite  de  feuillets,  et  dans  le  fait  qu'a  une 
telle  surface  congue  dans  toute  sa  generalite  correspond  une  classe  de 
courbes  algebriques.  De  plus,  on  pent  envisager  des  surfaces  de  Riemann 
a  un  nombre  infini  de  feuillets,  et  les  travaux  de  Poincare  ont  montre  le 


Troisieme  Conference.  251 

role  utile  qu'elles  peuvent  jouer  dans  I'etude  des  fonctions  non  uniformes. 
On  salt  aussi  I'importance  qu'avait  pour  Riemann  le  probleme  de  la  repre- 
sentation conforme ;  le  cas  de  la  representation  conforme  des  aires  a 
connexions  multiples  a  ete  traite  par  M.  Schottky  dans  un  tres  beau 
memoire  ou  I'auteur  se  montre  disciple  de  Weierstrass,  mais  qui  se  rat- 
tache  naturellement  a  I'ordre  d'idees  de  Riemann.  A  une  aire  plane 
percee  de  p  trous,  envisagee  comme  ayant  une  face  superieure  et  une  face 
inferieure  correspond  une  courbe  algebrique  de  genre  p ;  la  question  de 
la  representation  conforme  de  deux  aires  revient  alors  a  la  correspondance 
entre  les  points  de  deux  courbes  algebriques. 

Aux  courbes  algebriques  se  rattachent  des  fonctions  extremement  re- 
marquables  d'une  variable ;  ce  sont  les  fonctions  que  M.  Poincare  appelle 
fuchsiennes  et  que  M.  Klein  designe  sous  le  nom  de  fonctions  automorphes. 
Pour  les  courbes  des  genres  zero  et  un,  on  pent  exprimer  les  coordonnees 
par  des  fonctions  uniformes  d'un  parametre,  meromorphes  dans  tout 
le  plan  (fonctions  rationnelles  et  fonctions  doublement  periodiques). 
II  etait  naturel  de  chercher,  pour  les  courbes  de  genre  superieur  a  un,  une 
representation  parametrique  par  des  fonctions  uniformes.  Des  tentatives 
varices  out  probablement  ete  faites  pour  resoudre  cette  question,  en  cher- 
cliant  a  realiser  cette  expression  par  des  transcendantes  n'ayant  que  des 
poles  a  distance  finie.  De  telles  tentatives,  on  le  salt  aujourd'hui,  ne 
pouvaient  reussir,  car  on  pent  etablir  que,  entre  deux  fonctions  uniformes 
dans  le  voisinage  d'un  point  qui  est  pour  chacune  d'elles  un  point  singulier 
essentiel  isole,  ne  pent  exister  une  relation  algebrique  de  genre  superieur 
a  I'unite.  Les  transcendantes  a  employer  sont  d'une  nature  beaucoup 
plus  compliquee ;  les  unes  out  un  cercle  comme  coupure  au  dela  duquel 
elles  ne  peuvent  etre  prolongees  analytiquement,  les  autres  sont  definies 
dans  tout  le  plan,  mais  elles  ont  sur  un  cercle  une  infinite  de  points  singu- 
liers  essentiels  formant,  d'apres  la  denomination  de  M.  Cantor,  un  ensem- 
ble parfait  qui  n'est  pas  continu.  Les  celebres  memoires  de  M.  Poincare 
sur  les  fonctions  fuchsiennes  et  les  belles  recherches  de  M.  Klein  sur  le 
meme  sujet  ferment  un  des  plus  beaux  chapitres  ecrits  dans  ces  vingt 
dernieres  annees  sur  la  theorie  des  fonctions.  Les  fonctions  automorphes 
ferment  une  generalisation  extremement  etendue  et  remarquable  des  fonc- 
tions modulaires  etudiees  par  M.  Hermite  dans  la  theorie  des  fonctions 
elliptiques,  et  des  fonctions  considerees  par  M.  Schwarz  en  faisant  dans 
certains  cas  I'inversion  du  rapport  de  deux  solutions  de  I'equation  hyper- 
geometrique.     Toute   cette   theorie   est   d'ailleurs   etroitement  liee  a  la 


252  Emile  Picarcl : 

theorie  des  equations  lineaires,  et  c'est  un  des  resultats  les  plus  saillants 
obtenus  par  M.  Poincare  qu'avec  des  transcendantes  analogues  aux  fonc- 
tions  fuchsiennes  on  puisse  integrer  les  equations  differentielles  lineaires 
a  coefficients  algebriques  n'ayant  que  des  points  singuliers  reguliers  (au 
sens  de  M.  Fuchs). 

Parmi  les  transcendantes  se  rattachant  aux  fonctions  algebriques 
citons  encore  les  integrales  de  fonctions  a  multiplicateurs  etudiees  tout 
particulierement  par  M.  Appell.  Ce  sont  des  fonctions  n'ayant  sur  la 
surface  de  Riemann  que  des  poles  ou  des  points  singuliers  logarithmiques, 
et  dont  toutes  les  determinations  se  deduisent  de  I'une  d'entre  elles  par 
des  substitutions  de  la  forme  (ti,  au  +  h^;  elles  generalisent  par  suite  les 
integrales  abeliennes  pour  lesquelles  les  a  sont  egaux  a  I'unite.  Un  beau 
resultat  obtenu  par  M.  Appell  est  que  ces  fonctions  se  presentent  dans  la 
recherche  des  coefficients  des  fonctions  abeliennes  de  deux  variables  quand 
on  les  developpe  en  series  trigonometriques.  On  a  aussi  recherche  les  cas 
ou  I'inversion  d'une  integrale  de  fonction  a  multiplicateurs  conduit  a  une 
fonction  uniforme,  mais  la  conclusion  a  ete  negative,  c'est  a  dire  que  dans 
ce  cas  la  courbe  algebrique  est  necessairement  du  genre  zero  ou  du  genre 
un,  et  la  fonction  uniforme  obtenue  se  ramene  ou  des  transcendantes 
connues. 

IV. 

Les  equations  differentielles  forment  une  mine  inepuisable  pour  ob- 
tenir  des  fonctions  speciales.  Les  equations  lineaires  out  ainsi  conduit  a 
des  fonctions  jouissant  de  proprietes  bien  definies.  Pour  les  equations 
non  lineaires,  M.  Fuchs  appela  le  premier  I'attention  sur  les  equations 
algebriques  du  premier  ordre  a  points  critiques  fixes  et  montra  comment 
on  pent  reconnaitre  qu'on  se  trouve  dans  ce  cas.  M.  Poincare  fit  voir 
ensuite  qu'on  pouvait  ramener  ce  cas  a  des  quadratures  ou  aux  equations 
de  Riccati.  M.  Painleve  a  etendu  ces  resultats  en  considerant  les  equa- 
tions du  premier  ordre  dont  les  integrales  n'ont  qu'un  nombre  limite  de 
valeurs  autour  de  I'ensemble  des  points  critiques  mobiles.  Une  des  con- 
clusions de  ses  recherches  est  que  I'integrale,  supposee  trauscendante,  de 
toute  equation  algebrique  du  premier  ordre  qui  satisfait  a  la  condition 
precedente,  est  une  fonction  algebrique  de  I'integrale  d'une  equation  de 
Riccati  dont  les  coefficients  dependent  algebriquement  de  ceux  de  I'equa- 
tion  donnee.  On  peut  se  proposer  des  problemes  analogues  pour  les 
equations  differentielles  algebriques  d'ordre  superieur  au  premier.  II  se 
presente  ici  des  difficultes  considerables;  I'une  d'elles  tient  au  fait  suivant : 


Troisieme  Conference.  253 

tandis  que  toute  transformation  biuniforme  d'une  courbe  algebrique  en 
elle-meme  (avec  singularites  isolees)  est  necessairement  birationnelle,  il 
pent  arriver  au  contraire  qu'une  transformation  biuniforme  d'une  surface 
algebrique  en  elle-raeme  ne  soit  pas  birationnelle.  Une  seconde  difficulte, 
non  moins  grave,  consiste  dans  I'existence  possible  de  singularites  essen- 
tielles  mobiles.  J'ai  indique  hier  la  distinction  faite  a  cet  egard  par  M. 
Painleve  entre  la  classe  generale  d'equations  ne  possedant  pas  de  tels 
points  et  la  classe  singuliere. 

En  cherchant  a  etendre  aux  equations  du  second  ordre  a  points 
critiques  fixes  la  metliode  qui  avait  reussi  a  M.  Poincare  pour  les  equa- 
tions du  premier  ordre  jouissant  de  la  meme  propriete,  on  est  arrete  imme- 
diatement  par  la  premiere  difficulte  signalee  plus  haut,  et  c'est  seulement 
dans  le  cas  ou  I'integrale  generale  de  I'equation  est  supposee  dependre 
algebriquement  des  deux  constantes  d'integration  que  Ton  pent  pour- 
suivre  I'etude  sans  de  serieuses  difficultes  ;  on  retombe  d'ailleurs  sur  des 
transcendantes  deja  connues.  M.  Painleve  a  fait  une  etude  complete  des 
autres  cas  qui  peuvent  se  presenter  ;  I'integrale  generale  peut  encore  etre 
une  fonction  algebrique  d'une  seule  des  constantes,  ou  enfin  dependre 
d'une  maniere  transcendante  des  deux  constantes  (de  quelque  fagon  qu'on 
les  choisisse).  Ce  dernier  cas  seul  est  irreductible  aux  transcendantes 
classiques,  c'est  a  dire  ne  peut  etre  ramene  aux  quadratures  et  aux  equa- 
tions lineaires.  Ce  cas  se  presente  d'ailleurs  effectivement,  et  M.  Pain- 
leve a  forme  explicitement  toutes  les  equations  du  second  ordre  de  la 
forme 

y"  =  Riy^  y\  ^} 

ou  B  est  rationnel  en  ?/',  algebrique  en  y  et  analytique  en  x  ;  elles  se 
laissent  ramener  a  douze  types  canoniques  tres  simples.  J'indiquerai 
seulement  deux  de  ces  equations  pour  lesquelles  I'integrale  generale  est 
uniforme, 

1/"  =z  Qy^  -\-  X 

y"  =  2y^  -{■  xy  +  a  (a  =  constante  numerique) 

L'integrale  generale  de  I'une  et  I'autre  equation  est  une  fonction  uni- 
forme et  meromorphe  de  x  dans  tout  le  plan,  et  cette  integrale  est  une 
transcendante  vraiment  nouvelle.  Ces  exemples  precis  montrent  com- 
bien  M.  Painleve  a  pousse  jusqu'au  bout  ses  profondes  recherches. 

Je  me  bornerai  a  dire,  relativement  aux  equations  du  troisieme  ordre, 
que  I'integrale  generale  peut  avoir  des  lignes  de  points  singuliers  essen- 


254  Emile  Picard: 

tiels.  On  en  a  facilement  des  exemples  en  considerant  I'equation  diffe- 
rentielle  algebrique  du  troisieme  ordre  a  laquelle  satisfait  une  fonction 
automorphe  d'une  variable. 


Le  champ  des  fonctions  speciales  de  plusieurs  variables  complexes, 
dont  I'etude  a  ete  quel  que  peu  approfondie,  est  assez  limite.  La  theorie 
des  fonctions  abeliennes  a  fait  Tobjet  d'un  nombre  considerable  de  tra- 
vaux  qui  sont  trop  classiques  pour  que  je  m'y  arrete  ici ;  les  memoires 
de  Riemann  et  de  Weierstrass,  les  etudes  de  M.  Hermite  sur  la  transfor- 
mation des  fonctions  abeliennes  sont  dans  toutes  les  memoires.  Apres 
les  etudes  faites  sur  les  fonctions  fuchsiennes  d'une  variable,  il  etait 
naturel  de  chercher  des  transcendantes  analogues  pour  le  cas  de  deux 
variables  ;  on  devait  d'abord  se  demander  s'il  existe  des  groupes  discon- 
tinus  contenus  dans  le  groupe  lineaire  a  deux  variables 

/  a'u  +  h'v  +  c     a"u  -\-h"v  +  c"\  .. . 

(w,  v;  — - — — ,    — ■ I.  {1) 

\  au  +  ov  +  c      au  +   bv  -\-  e  J 

Un  seul  exemple  d'un  tel  groupe,  mais  bien  peu  utile,  s'offrait  a 
I'esprit,  celui  du  groupe  a  quatre  periodes.  Aucun  exemple  analogue 
au  groupe  modulaire  ne  se  presentait,  et  il  n'y  avait  rien  a  demander 
sur  ce  point  a  la  theorie  des  fonctions  abeliennes,  au  moins  sous  sa  forme 
classique.  Par  quoi  d'ailleurs  se  trouverait  remplacee  ici  la  condition 
imposee  aux  substitutions  d'un  groupe  fuchsien,  de  conserver  un  certain 
cercle  ?  L'etude  des  formes  quadratiques  ternaires  a  indeterminees  con- 
juguees  vint  permettre  de  former  en  grand  nombre  les  exemples  cher- 
chees.  M.  Hermite  avait,  il  y  a  longtemps,  montre  I'interet  au  point 
de  vue  arithmetique  des  formes  quadratiques  binaires  a  indeterminees 
conjuguees  ;  les  formes  ternaires  indefinies  conduisirent  a  de  nombreux 
groupes  du  type  (1),  discontinus  a  I'interieur  d'une  certaine  hypersurface 
de  I'espace  a  quatre  dimensions.  Cette  surface  remplace  la  circonference 
de  la  theorie  des  groupes  fuchsiens.  Les  groupes  du  type  precedent 
furent  appelees  groupes  hyperfuchsiens ;  on  se  rend  aisement  compte  que 
leur  recherche  generale  constitue,  comme  pour  les  groupes  fuchsiens,  un 
probleme  uniquement  d'ordre  algebrique ;  mais,  toute  representation 
geometrique  faisant  defaut,  cette  recherche  directe  serait  tellement 
penible  qu'elle  est  reellement  impraticable.  Aussi  les  exemples  fournis 
par   des   considerations    arithmetiques    sont-ils    extremement    precieux. 


Troisieme  Conference.  255 

Aux  groupes  hyperfuchsiens  correspondent  des  fonctions  uniformes 
restant  invariables  par  les  substitutions  du  groupe. 

Des  exemples  de  fonctions  hyperfuchsiennes  d'une  nature  differente 
peuvent  etre  fournis  par  les  series  hypergeometriques  de  deux  variables. 
Una  telle  serie,  fonction  de  a;  et  3/  dependant  de  quatre  parametres  arbi- 
traires  X,  yu.,  hy,  et  h,^  satisfait  a  un  systeme  de  trois  equations  lineaires  aux 
derivees  partielles  du  second  ordre,  ayant  trois  solutions  communes 
lineairement  independantes.  Designant  celles-ci  par  Wj,  Og,  6)3,  on  peut 
cliercher  dans  quels  cas  les  quotients 

donnent  pour  x  et  y  des  fonctions  uniformes  de  u  et  v.  Les  conditions 
sont  tres  simples  ;  si  on  prend  deux  quelconques  des  quatre  quantites 
\,  /A,  5j  et  ^2?  soit,  par  exemple  \  et  5^,  la  difference  X  +  6j  —  1  doit  etre 
I'inverse  d'un  nombre  entier  positif,  et  pareillement  si  on  prend  trois 
quelconques  de  ces  quantites,  soit  X,  n  et  h^  la  difference  2  —  X  —  /x  —  5j 
est  encore  egal  a  I'inverse  d'un  entier  positif.  Je  citerai  I'exemple 
\z=  ix  =  h-^  =  h^  =  ^  pour  lequel  le  polyedre  f ondamental  du  groupe  est 
tout  entier  a  Vinterieur  de  I'hypersurface  limite. 

On  peut  generaliser  les  fonctions  fuchsiennes  en  considerant  d'autres 
groupes  discontinus  que  les  groupes  hyperfuchsiens.  Une  substitution 
birationnelle  entre  deux  variables  u  Qt  v  n'est  pas  necessairement  lineaire, 
et  ce  serait  un  probleme  interessant  mais  difficile  de  former  tous  les 
groupes  discontinus  au  moins  dans  une  certaine  region  de  I'hyperespace 
(w,  V)  de  substitutions  birationnelles.  En  dehors  des  groupes  lineaires 
(hyperfuchsiens)  on  a  seulement  considere  jusqu'ici  les  groupes  formes 
de  substitutions  de  la  forme 


/     au-^h\     (     a'v  -\-h'\ 
r'^^TM/    V  c'v  +  d'J 


et  des  substitutions  ou  u  est  remplace  par  une  fonction  lineaire  de  v  et 
inversement.  Ce  sont  les  groupes  hyperabSliens  qui  rentrent  evidemment 
dans  les  types  des  substitutions  quadratiques  ;  il  y  a  dans  ce  cas  deux 
domaines  frontieres.  II  y  aura  sans  doute  des  decouvertes  interessantes 
a  faire  un  jour  dans  le  champ  tres  vaste  des  groupes  discontinus  de  sub- 
stitutions birationnelles,  et  des  fonctions  correspondantes  (dans  le  cas 
ou  il  en  existera,  comme  il  arrive  pour  les  fonctions  hyperfuchsiennes 
et  hyperabeliennes). 


256  Emile  Picard: 

VI. 

Nous  avons  rappele  tout  a  I'heure  le  brillant  d^veloppement  de  la 
theorie  des  fonctions  algebriques  d'une  variable ;  les  progres  ont  ete 
beaucoup  plus  lents  dans  le  champ  de  deux  variables.  C'est  un  sujet 
en  pleine  elaboration,  et  que  Ton  attaque  de  plusieurs  cotes.  Clebsch, 
se  plagant  au  point  de  vue  de  la  geometric  analytique,  signala  le  premier 
que,  pour  une  surface  algebrique  de  degre  m,  certaines  surfaces  d'ordre 
w  —  4  devaient  jouer  le  role  que  jouaient  les  adjointes  d'ordre  m  —  3  par 
rapport  a  une  courbe  de  degre  m.  L'etude  de  ces  surfaces  d'ordre  tw  —  4 
a  ete  reprise  par  M.  Noether  dans  un  memoire  de  grande  importance. 
En  se  plaQant  au  point  de  vue  de  la  theorie  des  fonctions,  voici  I'origine 
de  ces  surfaces.     Si  on  cherche  les  integrales  doubles 

J  J  R(x,  y,  z)dx  dy         (J(x,  y,  z)  =  0) 

restant   toujours   finies,  integrales  qu'on  appelle  les  integrales   doubles 
de  premiere  espece,  on  trouve  qu'elles  sont  de  la  forme 


// 


Q(x,  y,  z)dxdy 


Q  etant  un  polynome  d'ordre  w  —  4.  Le  nombre  pg  de  ces  polynomes 
lineairement  independants  est  ce  que  I'on  appelle  le  genre  gSomStrique 
de  la  surface  ;  un  pareil  nombre  est  manifestement  un  invariant.  Jus- 
qu'ici  les  analogies  sont  completes  avec  les  courbes  ;  il  y  a  des  integrales 
doubles  de  premiere  espece,  comme  il  y  a  des  integrales  abeliennes  de 
premiere  espece.  Mais  une  premiere  difference  va  de  suite  se  manifester. 
II  faut  calculer  le  nombre  des  arbitraires  qui  figurent  dans  les  poly- 
nomes Q  d'ordre  w  —  4  se  comportant  aux  points  multiples  de  la  sur- 
face de  telle  maniere  que  I'integrale  reste  finie.  Or  on  pent  trouver  par 
une  formule  precise  le  nombre  des  conditions  ainsi  entrainees,  mais  seule- 
ment  pour  un  polynome  d'un  ordre  suffisamment  grand  N;  si  done  on 
fait  dans  cette  formule  iV  =  m  —  4,  il  est  possible  que  Ton  trouve  un 
nombre  different  de  pg  ;  on  designe  le  nombre  que  donne  la  formule  a 
laquelle  je  fais  allusion  par  j9„,  et  on  I'appelle  le  genre  numerique  de 
la  surface.  Le  cas  le  plus  general  est  celui  ou  Pn=Pgl  quand  il  n'y 
a  pas  egalite,  on  a  Pn<Pg  et  la  surface  est  dite  irreguliere,  tandis  qu'elle 
est  reguiiere  si  p^  =  pg.  Cay  ley  a  le  premier  appele  I'attention  sur  la 
curieuse  circonstance  qui  precede ;  Zeuthen  et  Noether  etablirent  ensuite 


Troisihne  Conference.  257 

rinvariance  du  nombre  p^i  quand  il  n'est  pas  egal  a  pg.  Les  surfaces 
reglees  offrent  un  exemple  de  surface  irreguliere  ;  en  designant  par  ir 
le  genre  d'une  section  plane  arbitraire  de  la  surface,  on  a 

^„  =  -7r,    Pg=0. 

II  y  a  pour  une  surface  des  polynomes  adjoints  d'ordre  quelconque. 
On  peut  les  definir  facilement  au  point  de  vue  transcendant.  Si  la  surface 
a  une  position  arbitraire  par  rapport  aux  axes,  le  polynome  P(x^  y,  z) 
sera  un  polynome  adjoint  si  I'integrale  double 


// 


7^^ 


reste  finie  a  distance  finie ;  la  surface  P  =  0  est  une  surface  adjointe. 
M.  Enriques  a  donne  une  tres  remarquable  interpretation  geometrique 
de  la  difference  pg  —  p^-  Les  adjointes  d'ordre  m  —  4  +  r  decoupent  sur 
une  section  plane  determinee  d'ailleurs  arbitraire  une  serie  lineaire  de 
groupes  de  points  qui  peut  n'etre  pas  complete  si  r  est  assez  petit.  De- 
signons  par  w^  le  defaut  de  cette  serie  lineaire  par  rapport  a  la  serie  com- 
plete ;  on  a 


r  =  l 


la  somme  dans  le  second  membre  ne  comprend  qu'un  nombre  limite  de 
termes,  les  a>  etant  certainement  nuls  a  partir  d'une  valeur  assez  grande 
de  r.  La  formule  precedente  est  fondamentale  dans  I'etude  du  genre 
numerique. 

Nous  avons  parle  plus  haut  des  integrales  doubles  de  premiere  espece 
relatives  a  une  surface.  On  peut  aussi  developper  une  theorie  des  inte- 
grales doubles  de  seconds  espece  dont  la  definition  est  la  suivante:  ce  sont 
les  integrales  qui  deviennent  infinies  comme 


//i 


(f.gT)...,  (.) 


U  et  V  etant  des  fonctions  rationnelles  de  x,  i/  et  z  [/(ic,  y,  2)  =  0] .  Le 
nombre  des  integrales  distinctes  de  seconde  espece,  c'est  a  dire  des 
integrales  dont  aucune  combinaison  lineaire  n'est  de  la  forme  (a)  est 
fini ;  c'est  un  invariant  de  la  surface.  Mais  il  n'en  est  plus  ici,  comme 
dans  le  cas  des  courbes  pour  lesquelles  le  nombre  des  integrales  abe- 
liennes  distinctes  de  seconde  espece  etait  egale  k  2p;  le  nouvel  invariant 


258  Emile  Picard: 

d'une  classe  de  surfaces  algebriques  n'est  pas  lie  au  genre,  soit  geome- 
trique  soit  numerique. 

La  consideration  des  integrales  doubles  ne  se  presente  pas  seule.     On 
pent  aussi  envisager  des  integrales  de  differentielles  totales  de  la  forme 


j^P  (x,  y,  z)dx+Q  (x,  y,  z)  dy 


ou  P  et  ^  sont  rationnelles  en  x,  y  et  2,  et  il  y  a  encore  lieu  de  parler  des 
integrales  de  premiere  et  de  seconde  espece.  Mais  ici  de  telles  integrales 
n'existent  pas  en  general,  c'est  a  dire  pour  une  surface  prise  arbitraire- 
ment,  et  c'est  une  question  assez  delicate  que  de  reconnaitre  si  une  surface 
possede  des  integrales  de  seconde  espece  en  dehors  des  fonctions  ration- 
nelles. 

Les  questions  de  connexite  presentent  aussi  un  grand  interet  dans  la 
theorie  des  fonctions  algebriques  de  deux  variables  independantes,  mais 
quelques  precautions  sont  ici  necessaires.  Pour  une  surface  determinee, 
et  en  procedant  d'une  maniere  bien  precisee,  on  pent  obtenir  deux  nombres 
correspondant  a  la  connexion  lineaire  et  a  la  connexion  a  deux  dimen- 
sions ;  le  premier  p^  est  veritablement  un  invariant  pour  toute  transfor- 
mation birationnelle,  tandis  que  le  second  p^  pent  etre  influence  par  la 
presence  de  points  fondamentaux  dans  la  correspondance  birationnelle. 
C'est  un  resultat  remarquable  que  le  nombre  j^i  —  1  represente  le  nombre 
des  integrales  de  differentielles  totales  distinctes  de  seconde  espece  rela- 
tives a  la  surface.  Pour  une  surface  arbitrairement  choisie,  il  n'y  a  pas 
d'integrale  de  seconde  espece  et  on  o.  p^  =  1. 

On  voit  que  les  points  de  vue  de  la  geometric  analytique,  de  la  theorie 
des  fonctions  et  de  la  geometric  de  situation  se  retrouvent  aussi  dans 
I'etude  des  surfaces  algebriques,  mais  il  faut  se  mefier  des  analogies  avec 
la  theorie  des  courbes.  Tout,  dans  ce  nouveau  domaine,  se  presente 
d'une  maniere  plus  compliquee. 

Voici  encore  un  exemple  de  cette  complexite.  Les  courbes  dont  le 
genre  est  nul  forment  la  classe  tres  restreinte  des  courbes  unicursales. 
Au  contraire  les  surfaces  pour  les  quelles  jt?^  =  0  sont  extremement  varices, 
et  on  pent  dans  ce  cas  considerer  un  nouvel  invariant  que  M.  Enriques  a 
decouvert  et  qu'il  appelle  le  higenre.  On  pent  le  definir  aisement  dans  le 
cas  ou  la  surface  /  de  degre  m  n'a  qu'une  ligne  double.  On  envisagera  a 
cet  effet  le  systeme  des  surfaces  d'ordre  2  w  —  8  (ne  se  composant  pas  de 
/  et  d'une  surface  d'ordre  w  —  8)  ayant  comme  ligne  double  la  courbe 


Troisieme  Conference.  259 

double  de  /;  le  bigenre  P  est  la  dimension  augmentee  d'une  unite  de  ce 
systeme.  Cette  notion  a  permis  a  M.  Castelnuovo  d'etablir  un  theoreme 
reellement  merveilleux ;  il  s'agit  des  conditions  necessaires  et  suffisantes 
pour  qu'une  surface  soit  unicursale.  On  pouvait  penser  que  ces  con- 
ditions seraient  tres  compliquees  et  non  susceptibles  d'une  forme  simple ; 
il  n'en  est  rien,  elles  se  reduisent  a  j9„  =  0,  P  =  0.  Mais  je  dois  m'arreter, 
me  bornant  a  citer  seulement  le  memoire  si  elegant  de  M.  Humbert  sur 
les  surfaces  hyperelliptiques  qui  donnent  un  tres  interessant  exemple  de 
surfaces  irregulieres  pour  les  quelles  p„  =  —  1,  tandis  que  pg=l. 

Nous  avons,  messieurs,  jete  un  rapide  coup  d'oeil  sur  quelques  unes 
des  branches  de  la  science  mathematique.  Vous  avez  pu  vous  apercevoir 
plus  d'une  fois  de  I'embarras  dans  lequel  je  me  suis  trouve,  quand  j'ai 
voulu,  pour  les  necessites  de  mon  exposition,  faire  une  classification  dans 
certaines  theories.  La  penetration  reciproque  des  diverses  disciplines  est 
aujourd'hui  en  effet  un  fait  capital  et  sera  de  plus  en  plus  la  source  d'im- 
portantes  decouvertes.  A  cet  egard,  il  y  a  une  grande  difference  entre 
notre  epoque  et  des  temps  un  peu  anterieurs.  Nous  avons  peine  aujour- 
d'hui a  comprendre  certaines  histoires  ou  on  voit  des  geometres  mepriser 
des  analystes  et  inversement ;  nous  sentons  que  I'ere  des  ecoles  fermees  et 
etroitement  attachees  a  un  seul  point  de  vue  est  pour  toujours  terminee. 
II  est  bien  vraisemblable  que  I'erudition  jouera  a  I'avenir  un  plus  grand 
role  qu'autrefois  en  mathematiques.  Les  mathematiciens  perdront  peut- 
etre  ce  privilege  de  la  precocite  qui  etonne  tant  de  personnes  ;  ils  se 
rapprocheront  des  physiciens  et  des  naturalistes  qui  doivent  en  general 
commencer  plus  tard  leurs  travaux  personnels.  En  terminant,  je  me 
permettrai  de  donner  un  conseil  aux  etudiants  mathematiciens  qui  m'ont 
fait  I'honneur  de  m'ecouter  ;  je  leur  recommanderai  de  ne  pas  se  can- 
tonner  trop  tot  dans  des  recherches  speciales.  II  leur  faut  acquerir 
d'abord  des  vues  generales  sur  les  diverses  parties  de  notre  science,  sans 
lesquelles  leurs  efforts  risqueraient  de  rester  steriles,  et  qui  leur  coiite- 
raient  plus  tard  un  bien  plus  grand  effort. 


.-£^.£4^^- 


tJBER  DIE    GRUNDPRINCIPIEN   UND   GRUND- 
GLEICHUNGEN   DER   MECHANIK. 

Von  Professor  Ludwig  Boltzmann. 


Ekste  Vorlestjng. 

Die  analytische  Mechanik  ist  eine  Wissenschaft,  welche  schon  von 
ihrem  Begriinder  Newton  mit  solchem  Scharfsinne  und  soldier  Vollen- 
dung  ausgearbeitet  wurde  wie  es  in  dem  gesaramten  Gebiete  menschlichen 
Wissens  fast  ohne  Beispiel  dasteht.  Die  grossen  Meister,  welche  auf 
Newton  folgten,  haben  das  von  ihm  errichtete  Gebaude  noch  weiter 
gefestigt,  und  es  hatte  den  Anschein,  dass  eine  vollendetere  und  einheit- 
lichere  Schopfung  des  Menschengeistes  als  die  Grundlehren  der  Me- 
chanik, wie  sie  uns  in  den  Werken  von  Lagrange,  Laplace,  Poisson, 
Hamilton  etc.  entgegentreten  iiberhaupt  nicht  denkbar  ware.  Gerade 
die  Begriindung  der  ersten  Principien  schien  von  diesen  Forschern 
mit  einem  Scharfsinne  und  einer  logischen  Consequenz  durchgefiihrt,  die 
allezeit  das  Vorbild  lieferten,  welchem  man  die  Begriindung  der  iibrigen 
Wissenszweige,  wenn  auch  nicht  immer  mit  dem  gleichen  Erfolge,  nach- 
zubilden  suchte,  Es  schien  lange  ganz  unmoglich  dieser  Begriindung 
iiberhaupt  noch  etwas  hinzu  zu  fiigen  oder  daran  etwas  zu  andern. 

Um  so  auffallender  und  unerwarteter  ist  es,  dass  gegenwartig  haupt- 
sachlich  in  Deutschland  ziemlich  lebhafte  Controversen  gerade  iiber  die 
Grundprincipien  der  analytischen  Mechanik  entstanden  sind.  Es  ist 
dies  gewiss  nicht  so  zu  verstehen,  als  ob  die  Ehrfurcht  und  Bewunde- 
rung,  die  wir  dem  Genius  eines  Newton,  Lagrange  oder  Laplace  zollen, 
dadurch  irgend  wie  geschmalert  werden  sollte.  Diese  haben  aus  den 
kleinen  Anfangen,  welche  sie  vorfanden,  eine  fiir  alle  Zeiten  mustergiil- 
tige  Herrin  geschaffen.  Sie  hatten  so  viel  des  thatsachlich  Neuen  heraus 
zu  arbeiten,  dass  sie  sich  nur  aufgehalten  und  dem  einheitlichen  Ein- 
druck  geschadet  hatten,  wenn  sie  bei  gewissen  Schwierigkeiten  und 
Dunkelheiten  zu  lange  verweilt  hatten.     Aber  seitdem  ist  unsere  Kennt- 

261 


262  Ludwig  Boltzmann: 

nis  von  Thatsachen  bedeutend  gewachsen,  unser  Verstand  ist  geschult, 
so  dass  viele  Vorstellungen,  welclie  zu  Zeiten  Newtons  noch  den  Gelehr- 
ten  Schwierigkeiten  machten,  nun  zum  Gemeingut  aller  geworden  sind. 
Dadurch  erhielt  man  Musse  die  Construktion  des  Newton'schen  Gebaudes 
gewissermassen  mit  der  Lupe  zu  betrachten,  und  siehe  es  ergaben  sich 
manche  Schwierigkeiten,  wie  sie  sich  ja  dem  Menschengeiste  immer 
gerade  da  am  meisten  entgegen  stellen,  wo  er  die  einfachsten  Grund- 
lagen  der  Erkenntnis  zu  analy siren  strebt. 

Diese  Schwierigkeiten  sind  f reilich  mehr  philosophischer  oder  wie  man 
heutzutage  sagt,  erkenntnistheoretischer  Natur.  Wir  Deutsche  sind 
schon  oft  und  viel  verlacht  worden  wegen  unserer  Neigung  zur  philoso- 
phischen  Speculation  und  in  friiherer  Zeit  sicher  oft  mit  Recht.  Eine  von 
den  Thatsachen  abgekehrte  Philosophic  hat  nie  etwas  Brauchbares  hervor- 
gebracht  und  kann  es  nicht  hervorbringen.  Von  unmittelbar  greifbarem 
Nutzen  ist  es  vor  allem,  unsere  Kenntnis  der  Thatsachen  durch  Experi- 
mente  zu  erweitern  und  auch  unsere  wissenschaf tliche  Naturkenntnis  wird 
zunachst  und  am  ausgiebigsten  in  dieser  Weise  gefordert.  Aber  trotz 
alledem  scheint  die  Neigung  die  einfachsten  Begriffe  zu  analysiren  und 
sich  iiber  die  Grundoperationen  unseres  Denkens  Rechenschaft  zu  geben 
im  Menschengeiste  unbezwinglich. 

Viel  hat  sich  auch  die  Methode  dieser  Analyse  im  Verlauf  e  der  Zeit  ver- 
vollkommnet,  so  dass  dieselbe  heutzutage  weun  auch  noch  keineswegs  sof ort 
praktisch  fruchtbringend,  doch  lange  nicht  mehr  so  wesenlos  ist,  wie  die 
alte  Philosophic.  Im  Verlaufe  der  Geschichte  erfahrt  ja  das  ganze  Cultur- 
bild  der  Menschheit  stete  und  bedeutende  Schwankungen.  Die  Deutschen 
sind  nicht  mehr  die  unpraktischen  Traumer  von  ehemals.  Sie  haben  es 
auf  alien  Gebieten  der  Experimentalwissenschaft,  der  Technik,  Industrie, 
und  Politik  bewiesen.  Die  Bestrebungen  der  Amerikaner  waren  natur- 
gemass  anfangs  behufs  Unterjochung  des  Grundes  und  Bodens  der  rein 
praktischen  Thatigkeit  der  Industrie  und  Technik  zugewandt.  Aber 
sie  sind  es  langst  nicht  mehr  ausschliesslich  und  schon  weist  Amerika  auf 
alien  Gebieten  der  abstrakten  Wissenschaft  Forscher  auf,  die  den  hervor- 
ragensten  Europas  voUkommen  ebenburtig  zur  Seite  stehen.  Da  sie  daher, 
meine  Herren,  einen  Deutschen  zu  Vortragen  in  ihrem  Lande  geladen 
haben,  so  will  ich  es  wagen  ein  Gebiet  der  Erkenntnistheorie  mit  ihnen 
zu  betreten. 

Ich  will  zunachst  wieder  zuriick  kommen  auf  die  Bedenken,  welche 
gegen  die  Fundamente  der  Newton'schen  Mechanik  erhoben  worden  sind 


Erste  Vorlesung.  263 

oder  (besser  gesagt)  zu  den  Stellen,  wo  diese  noch  einer  naheren  Beleucht- 
ung,  einer  Analyse  der  Schlussweise  und  Sichtung  der  Begriffe  zu  bediir- 
fen  scheinen.  Bei  Aufstellung  der  Bewegungsgesetze  betrachtet  Newton 
die  Bewegung  der  Korper  als  eine  absolute  im  Raume.  Der  absolute 
Raum  ist  aber  nirgends  unserer  Erfahrung  zuganglich.  Erfahrungsmas- 
sig  gegeben  sind  immer  nur  die  relativen  Lagenanderungen  der  Korper. 
Es  wird  also  da  gleich  zu  Anfang  voUstandig  iiber  die  Erfahrung  hin- 
ausgegangen,  was  gewiss  bedenklicb  ist  in  einer  Wissenscliaft,  welche 
sich  nur  die  Aufgabe  stellt  Erfahrungsthatsachen  darzustellen.  Diese 
Schwierigkeit  ist  natiirlich  dem  Genius  Newtons  keineswegs  entgangen. 
Allein  dieser  glaubte  ohne  den  Begriff  eines  absoluten  Raumes  zu  keiner 
einfacben  Formulirung  des  Tragheitsgesetzes  gelangen  zu  konnen,  um 
die  es  ibm  an  erster  S  telle  zu  thun  war  und  ich  glaube,  dass  er  hierin  auch 
Recht  behalten  hat ;  denn  so  viel  diese  Schwierigkeit  auch  beleuchtet  oder 
durchdacht  wurde,  so  ist  doch  kaum  ein  wesentlicher  Fortschritt  erzielt 
worden.  Neumann  fiihrt  statt  des  Newton'schen  absoluten  Raumes  einen 
rathselhaften  idealen  Bezugskorper  ein,  womit  er  offenbar  ganz  ebenso 
wie  Newton  iiber  die  Erfahrung  hinausgeht.  Streintz  stellt  sich  die 
Aufgabe  derartige  Begriffe  oder  Korper  zu  vermeiden,  indem  er  lehrt 
wie  man  mittelst  der  Bewegung  eines  Gyroskops,  auf  welches  keine  oder 
bekannte  Krafte  wirken  relativ  gegen  ein  gewahltes  Coordinatensystem 
entscheiden  kann,  ob  fiir  dieses  Coordinatensystem  die  Newton'schen  Be- 
wegungsgesetze gelten,  ob  es  ein  brauchbares  Bezugssystem  ist.  Allein 
diese  Streintz'schen  Betrachtungen  scheinen  fiir  die  Fundamentirung  der 
Mechanik  wenig  brauchbar,  da  sie  ja  bereits  die  Bewegungsgesetze  ein- 
es rotirenden  Kreisels  und  die  Beurtheilung,  ob  auf  denselben  Krafte 
wirken  oder  nicht,  voraussetzen,  wozu  schon  die  Kenntnis  der  Newton'- 
schen Bewegungsgesetze  erforderlich  ist.  Lange  versucht  allerdings 
die  Formulirung  des  Tragheitsgesetzes  ohne  irgend  ein  Bezugssystem 
bloss  durch  Betrachtung  der  relativen  Bewegung.  Sie  gelingt  ihm  auch, 
fallt  aber  so  complicirt  und  weitschweifig  aus,  dass  man  sich  nur  schwer 
entschliessen  wird  ein  so  wenig  libersichtliches  Gesetz  an  Stelle  der  ein- 
facben Newton'schen  Formel  zu  setzen.  Selbstverstandlich  geht  auch 
der  Vorschlag  Mach's  Gerade,  welche  durch  die  Gesammtheit  aller  Mas- 
sen  der  Welt  bestimmt  sind  oder  der  Vorschlag  den  Lichtather  an  Stelle 
des  absoluten  Raums  zu  setzen,  beide  freilich  in  ganz  anderer  Weise  iiber 
die  Erfahrung  hinaus.  Ersterer  Vorschlag  kniipft  namlich  wieder  an 
rein  ideale  transcendente  Begriffe  an,  wogegen  letzterer  eine  Aussage 


264  lAidwig  Boltzmann: 

macht,  welche  zwar  erfahrungsmassig  moglicherweise  bewiesen  werden 
konnte,  aber  es  gewiss  noch  nicht  ist.  Es  miisste  derm  fiir  den  Ather 
eine  ganz  audere  Mechanik  gelten,  dieser  miisste  etwa  selbst  die  Ursache 
des  Tragheitsgesetzes  nicht  aber  demselben  unterworfen  sein.  Eine 
gleiche  Schwierigkeit  begegnet  man  bei  Einfiihrung  des  Begriffs  der 
Zeit.  Auch  diese  wird  von  Newton  als  eine  absolute  eingefiihrt,  wahrend 
uns  eine  solche  niemals  gegeben  ist,  sondern  immer  bloss  die  Gleicbzei- 
tigkeit  des  Verlaufs  mehrerer  Vorgange.  Jedoch  ist  bier  die  Abhilfe 
leichter,  indem  man  von  einem  Vorgange  ausgeht,  der  sich  immer  peri- 
odisch  unter  ganz  gleichen  Umstanden  wiederholt.  Freilich  ist  es  nicht 
moglich  absolute  Gleichheit  der  Umstande  herzustellen,  doch  kann  man 
im  hochsten  Grade  wahrscheinlich  machen,  dass  alle  Umstande,  die  iiber- 
haupt  wesentlichen  Einfluss  haben,  die  gleichen  sind.  Man  kann  dies 
noch  dadurch  erharten,  dass  man  verschiedenartige  Vorgange  von  dieser 
Eigenschaft  (die  Erddrehung,  die  Schwingungen  eines  Pendels,  einer 
Chronometerfeder)  untereinander  vergleicht.  Die  Ubereinstimmung  aller 
dieser  Vorgange  in  der  Anzeige  gleicher  Zeiten  schliesst  dann  jeden 
Zweifel  an  der  Brauchbarkeit  der  Methode  aus. 

Eine  dritte  Schwierigkeit  betrifft  die  Begriffe  der  Masse  und  Kraft. 
Dass  die  Newton'sche  Definition  der  Masse  als  Quantitat  der  Materie 
eine  nichts  sagende  ist,  wurde  langst  erkannt.  Aber  auch  beziiglich  des 
Verhaltnisses  der  Kraft  zur  Masse  ergeben  sich  Zweifel.  Ist  die  Masse 
das  allein  Existirende  und  die  Kraft  nur  eine  Eigenschaft  derselben  oder 
ist  umgekehrt  die  Kraft  das  wahrhaft  Existirende  oder  ist  ein  Dualismus 
zweier  getrennter  Existenzen  (Masse  und  Kraft)  anzunehmen,  so  dass  die 
Kraft  eine  von  der  Materie  getreunt  existirende  Ursache  der  Bewegung 
der  ersteren  ist.  Hinzu  kam  in  neuerer  Zeit  noch  die  Frage,  ob  auch 
der  Energie  Existenz  zuzuschreiben  ist  oder  ob  gar  letztere  das  allein 
Existirende  ist. 

Es  war  vor  alien  Kirchhoff,  welcher  in  diesem  Punkte  schon  der  Art 
der  Fragestellung  entgegentrat.  Oft  ist  ein  Problem  schon  halb  gelost, 
wenn  die  richtige  Methode  der  Fragestellung  gefunden  ist.  Kirchhoff 
wies  es  nun  zuriick,  dass  es  Aufgabe  der  Naturwissenschaft  sei,  das  wahre 
Wesen  der  Erscheinungen  zu  entriithseln  und  ihre  ersten  metaphysischen 
Grundursachen  anzugeben.  Er  reducirte  die  Aufgabe  der  Naturwissen- 
schaft vielmehr  darauf,  die  Erscheinungen  zu  beschreiben.  Kirchhoff 
nannte  dies  noch  eine  Beschrankung  der  Aufgabe  der  Naturwissenschaft. 
Wenn  man  aber  so  recht  in  die  Art  und  Weise,  ich  mochte  sagen  in  den 


Erste  Vorlesung.  265 

Mechanismus  unseres  Denkens  eindringt,  so  moclite  man  fast  auch  das 
leugnen. 

Alle  unsere  Vorstellungen  und  Begriffe  sind  ja  nur  innere  Gedanken- 
bilder,  wenn  ausgesprochen  Lautcombinationen.  Die  Aufgabe  unseres 
Denkens  ist  es  nun,  dieselben  so  zu  gebrauclien  und  zu  verbinden,  dass 
wir  mit  ihrer  Hilfe  allezeit  mit  grosster  Leichtigkeit  die  richtigen  Hand- 
lungen  treffen  und  audi  andere  zu  richtigen  Handlungen  anleiten.  Die 
Metaphysik  hat  sich  da  dem  niichternsten  praktischsten  Standpunkte 
angeschlossen,  die  Extreme  beriihren  sich.  Die  begrifflichen  Zeichen, 
welche  wir  bilden,  haben  also  nur  eine  Existenz  in  uns,  die  aussern 
Erscheinungen  konnen  wir  nicht  mit  dem  Masse  unserer  Vorstellungen 
messen.  Wir  konnen  also  formell  derartige  Fragen  aufwerfen,  ob  bloss 
die  Materie  existirt  und  die  Kraft  eine  Eigenschaft  derselben  ist  oder 
ob  letztere  von  der  Materie  unabhangig  existirt  oder  ob  umgekehrt  die 
Materie  ein  Erzeugnis  der  Kraft  ist ;  aber  es  haben  alle  diese  Fragen  gar 
keine  Bedeutung,  da  alle  diese  Begriffe  nur  Gedankenbilder  sind,  welche 
den  Zweck  haben  die  Erscheinungen  richtig  darzustellen.  Besonders 
klar  hat  dies  Hertz  in  seinem  beriihmten  Buche  uber  die  Principien  der 
Mechanik  ausgesprochen,  nur  stellt  Hertz  daselbst  als  erste  Forderung 
die  auf,  dass  die  Bilder,  welche  wir  uns  construiren,  den  Denkgesetzen 
entsprechen  miissen.  Gegen  diese  Forderung  mochte  ich  gewisse  Beden- 
ken  erheben  oder  wenigstens  sie  etwas  naher  erlautern,  Gewiss  miissen 
wir  einen  reichen  Schatz  von  Denkgesetzen  mitbringen.  Ohne  sie  ware 
die  Erfahrung  vollkommen  nutzlos;  wir  konnten  sie  gar  nicht  durch 
innere  Bilder  fixiren.  Diese  Denkgesetze  sind  uns  fast  ausnahmslos  ange- 
boren,  aber  sie  erleiden  doch  durch  Erziehung,  Belehrung,  und  eigene 
Erfahrung  Modifikationen.  Sie  sind  nicht  vollkommen  gleich  beim 
Kinde,  beim  einfachen  ungebildeten  Manne,  oder  beim  Gelehrten.  Wir 
werden  dies  auch  einsehen,  wenn  wir  die  Denkrichtung  eines  naiven  Volkes 
wie  der  Griechen  mit  der  der  Scholastiker  des  Mittelalters,  und  diese  wieder 
mit  der  heutigen  vergleichen.  Gewiss  gibt  es  Denkgesetze,  welche  sich 
so  ausnahmslos  bewahrt  haben,  dass  wir  ihnen  unbedingt  vertrauen,  sie 
fiir  aprioristische  unabanderliche  Denkprincipien  halten.  Aber  ich 
glaube  doch,  dass  sie  sich  erst  langsam  entwickelten.  Ihre  erste  Quelle 
waren  primitive  Erfahrungen  der  Menschheit  im  Urzustand,  allmiilig 
erstarkten  sie  und  verdeutlichten  sich  durch  complicirtirte  Erfahrungen 
bis  sie  endlich  ihre  jetzige  scharfe  Formulirung  annahmen  ;  aber  als  unbe- 
dingt oberste   Richter  mochte   ich   die  Denkgesetze  nicht  anerkennen. 


266  Ludwig  Boltzmann: 

Wir  konnen  nicht  wissen  ob  sie  nicht  doch  noch  die  eine  oder  andere 
Modification  erfahren  werden.  Man  erinnere  sich  doch  mit  welcher 
Sicherheit  Kinder  oder  Ungebildete  iiberzeugt  sind,  dass  man  durch  das 
blosse  Gefiihl  die  Richtung  nach  oben  von  der  nach  unten  an  alien  Orten 
des  Weltraums  miisse  unterscheiden  konnen  und  wie  sie  daraus  die 
Unmoglichkeit  der  Antipoden  deduciren  zu  konnen  glauben.  Wiirden 
solche  Leute  Logik  schreiben,  so  wiirden  sie  das  sicher  fiir  ein  a  priori 
evidentes  Denkgesetz  halten.  Ebenso  wurden  anfangs  gegen  die  Coper- 
nicanische  Theorie  vielfach  aprioristische  Bedenken  erhoben  und  die  Ge- 
schichte  der  Wissenschaft  weist  zahlreiche  Falle  auf,  wo  man  Siitze  bald 
begriindete,  bald  widerlegte  mittels  Beweisgriinden,  die  man  damals  fiir 
evidente  Denkgesetze  hielt,  wahrend  wir  jetzt  von  ilirer  Nichtigkeit  iiber- 
zeugt sind.  Ich  moclite  daher  die  Hertz'sche  Forderung  dahin  modificiren, 
dass  in  so  weit  wir  Denkgesetze  besitzen,  welche  wir  durch  stete  Bewahr- 
heitung  in  der  Erfahrung  als  zweifellos  richtig  erkannt  haben,  wir  die 
Richtigkeit  unserer  Bilder  zunachst  an  diesen  erproben  konnen,  dass 
aber  die  letzte  und  alleinige  Entscheidung  iiber  die  Zweckmassigkeit  der 
Bilder  in  dem  Umstande  liegt,  dass  sie  die  Erfahrung  moglichst  einfach 
und  durchaus  treffend  darstellen  und  dass  gerade  hierin  wieder  die  Probe 
fiir  die  Richtigkeit  der  Denkgesetze  liegt.  Haben  wir  die  Aufgabe  des 
Denkens  iiberhaupt  und  der  Wissenschaft  insbesondere  in  dieser  Weise 
erfasst,  so  ergeben  sich  uns  Consequenzen  welche  im  ersten  Augenblick 
etwas  Frappirendes  an  sich  haben.  Eine  Vorstellung  von  der  Natur  wer- 
den wir  falsch  nennen,  wenn  sie  uns  gewisse  Thatsachen  unrichtich  dar- 
stellt  oder  wenn  es  offenbar  einfachere  gibt,  welche  die  Thatsachen  klarer 
darstellen,  besonders  wenn  sie  allgemein  bewahrten  Denkgesetzen  wider- 
spricht,  doch  sind  immerhin  Theorien  moglich,  Avelche  eine  grosse  Zahl  von 
Thatsachen  richtig  darstellen  in  andern  Punkteu  aber  unrichtig  sind,  denen 
also  eine  gewisse  relative  Wahrheit  zukommt.  Ja  es  ist  sogar  moglich,  dass 
wir  in  verschiedener  Weise  ein  System  von  Bildern  der  Erscheinungen 
construiren  konnen.  Jedes  dieser  Systeme  ist  nicht  gleich  einfach,  stellt 
die  Erscheinungen  nicht  gleich  gut  dar.  Aber  es  kann  zweifelhaft, 
gewissermassen  Geschmacksache  sein,  welches  wir  fiir  das  Einfachere 
halten,  durch  welche  Darstellung  der  Erscheinungen  wir  uns  mehr  befrie- 
digt  fiihlen.  Die  Wissenschaft  verliert  hiedurch  ihr  einheitliches  Geprage. 
Man  hielt  doch  ehedem  daran  fest,  dass  es  nur  Eine  Wahrheit  geben 
konne,  dass  die  Irrthiimer  mannigfaltig  seien,  die  Wahrheit  aber  nur  eine 
einzige  ist.     Dieser  Ansicht  muss  von  unserem  jetzigen  Standpunkte  ent- 


Erste  Vorlesung.  267 

gegen  getreten  werden,  freilich  ist  der  Unterschied  der  neuen  Ansicht 
gegeniiber  der  alten  ein  mehr  formeller.  Es  war  nie  zweifelhaft,  dass  der 
Mensch  niemals  den  voUen  Inbegriff  aller  Wahrheit  zu  erkennen  vermoge. 
Diese  Erkenntniss  ist  nur  ein  Ideal.  Ein  ahnliches  Ideal  besitzen  wir  aber 
audi  gemass  unserer  jetzigen  Vorstellung.  Es  ist  das  vollkommenste  Bild, 
das  alle  Erscheinungen  in  der  einfachsten  und  zweckmassigsten  Weise 
darstellt.  Wir  wenden  daher  nach  der  einen  Anschauungsweise  den 
Blick  mehr  auf  das  unerreichbare  Ideal,  welches  nur  ein  einheitliches  ist, 
nach  der  andern  auf  die  Mannigfaltigkeit  des  Erreichbaren. 

Wenn  wir  nun  die  Uberzeugung  haben,  dass  die  Wissenschaft  bloss 
ein  inneres  Bild,  eine  gedankliche  Construction  ist,  welche  sich  mit 
der  Mannigfaltigkeit  der  Erscheinungen  niemals  decken,  sondern  nur 
gewisse  Theile  derselben  ubersichtlich  darstellen  kann,  wie  werden  wir 
zu  einem  solchen  Bilde  gelangen  ?  wie  es  moglichst  systematisch  und 
ubersichtlich  darstellen  konnen  ?  Es  war  friiher  eine  Methode  beliebt, 
welche  der  von  Euclid  in  der  Geometrie  angewandten  nachgebildet  ist 
und  daher  die  Euclidische  heissen  soil.  Dieselbe  geht  von  moglichst 
weuigen,  moglichst  evidenten  Satzen  aus.  In  den  altesten  Zeiten  wurden 
diese  als  a  priori  evident,  als  direkt  dem  Geiste  gegeben  betrachtet,  wess- 
halb  man  sie  als  Axiome  bezeichnet.  Spater  dagegen  schrieb  man  ihnen 
lediglich  den  Charakter  von  hinlanglich  verblirgten  Erfahrungssatzen 
zu.  Aus  diesen  Axiomen  wurden  dann  bloss  mit  Hilfe  der  Denkgesetze 
gewisse  Bilder  als  nothwendig  deducirt  und  man  glaubte  so  einen  Beweis 
gefunden  zu  haben,  dass  diese  die  einzig  moglichen  seien  und  nicht  durch 
andere  ersetzt  werden  konnten.  Als  Beispiel  fiihre  ich  die  Schliisse  an, 
welche  zur  Ableitung  des  Krafteparallelogramms  oder  des  Ampere'schen 
Gesetzes  oder  des  Beweises  dienten,  dass  die  zwischen  zwei  materiellen 
Punkten  wirkende  Kraft  in  die  Richtung  ihrer  Entfernung  fallen  und 
eine  Function  dieser  Entfernung  sein  miisse. 

Aber  die  Beweiskraft  dieser  Schlussweise  geriet  allmalig  in  Miscredit, 
der  erste  Schritt  hiezu  war  der,  dass  man  wie  schon  friiher  geschildert 
von  einer  a  priori  evidenten  Grundlage  zu  einer  bloss  erfahrungsmassig 
bewahrten  liberging.  Man  sah  ferner  ein,  dass  auch  die  Deduktionen  aus 
jener  Grundlage  nicht  ohne  zahlreiche  neue  Hypothesen  gemacht  werden 
konnten,  und  so  wies  endlich  Hertz  darauf  hin,  dass  namentlich  im  Gebiete 
der  Physik  unsere  Uberzeugung  von  der  Richtigkeit  einer  allgemeinen 
Theorie  im  Wesen  noch  nicht  auf  der  Ableitung  derselben  nach  der 
Euclidischen  Methode,  sondern  vielmehr  darauf  beruhe,  dass  diese  Theo- 


268  Ludwig  Boltzmann: 

rie  in  alien  bisher  bekannten  Fallen  uns  zu  riclitigen  Schliissen  in  Bezug 
auf  die  Erscheinungen  leite.  Er  machte  von  dieser  Ansicht  zuerst  in 
seiner  Darstellung  der  Maxwell'schen  Grundgleichungen  der  Lehre  von  der 
Elektricitat  und  dem  Magnetisraus  Gebrauch,  indem  er  vorschlug  sicli  um 
deren  Ableitung  aus  gewissen  Grundprincipien  gar  nicht  zu  bekiimmern, 
sondern  sie  einfach  an  die  Spitze  zu  stellen  und  die  Rechtfertigung  hie- 
von  darin  zu  suchen,  dass  man  nachweisen  konne  dass  sie  hinterher  iiber- 
all  mit  der  Erfahrung  iibereinstimme ;  denn  diese  bleibt  docli  scliliesslich 
die  einzige  Richterin  liber  die  Brauchbarkeit  einer  Theorie,  deren  Urtheil 
inapellabel  und  unerschiitterlich  ist.  In  der  That  wenn  wir  auf  die  Gegen- 
stande  naher  eingehen,  welche  mit  dem  Gegenstande  am  meisten  zusam- 
menhangen,  das  Tragheitsgesetz,  das  Kriifteparallelogramm  und  die  libri- 
gen  Fundamentalsatze  der  Mechanik,  so  werden  wir  die  verschiedenen 
Beweise,  welche  in  alien  Lehrblichern  der  Mechanik  fiir  jeden  einzelnen 
dieser  Satze  geliefert  werden,  bei  weitem  nicht  so  liberzeugend  fiuden,  als 
die  Thatsache,  dass  sich  alle  aus  dem  Inbegriffe  aller  dieser  Satze  gezo- 
genen  Consequenzen  so  ausgezeichnet  in  der  Erfahrung  bestatigt  haben. 
Die  Wege,  auf  denen  wir  zu  den  Bildern  gelangten,  sind  nicht  selten  die 
verschiedensten  und  von  den  mannigfaltigsten  Zufiillen  abhangig. 

Manche  Bilder  wurden  im  Verlauf  von  Jahrhunderten  durch  das  Zu- 
sammenwirken  vieler  Forscher  erst  allmiilig  construirt,  wie  die  der  mecha- 
nischen  Warmetheorie.  Manche  wurden  von  einem  einzigen,  genialen  For- 
scher, aber  oft  wieder  auf  sehr  verschlungenen  Umwegen,  gefunden  und 
erst  dann  von  andern  in  die  verschiedenartigste  Beleuchtung  geriickt, 
wie  die  besprochene  Maxwell'sche  Theorie  der  Elektricitat  und  des 
Magnetismus.  Es  wird  nun  eine  Darstellungsweise  geben,  welche  ganz 
besondere  Vorziige  aber  audi  wieder  ihre  Mangel  besitzt.  Diese  Dar- 
stellungsweise besteht  darin,  dass  wir  eingedenk  unserer  Aufgabe,  bloss 
innere  Vorstellungsbilder  zu  construiren,  anfangs  lediglich  mit  gedank- 
lichen  Abstractionen  operiren.  Hiebei  nehmen  wir  noch  gar  keine  Riicksicht 
auf  etwaige  Erfahrungsthatsachen.  Wir  bemiihen  uns  lediglich  mit  mog- 
lichster  Klarheit  unsere  Gedankenbilder  zu  entwickeln,  und  aus  denselben 
alle  moglichen  Consequenzen  zu  ziehen.  Erst  hinterher,  nachdem  die 
ganze  Exposition  des  Bildes  vollendet  ist,  priifen  wir  dessen  Ubereinstim- 
mung  mit  den  Erfahrungsthatsachen,  motiviren  also  in  dieser  Weise  erst 
hinterher,  warum  das  Bild  gerade  so  und  nicht  anders  gewiihlt  werden 
musste,  woriiber  wir  vorher  nicht  die  leiseste  Andeutung  geben.  Wir 
wollen  dies  als  die  deduktive  Darstellung  bezeichnen.   Die  Vorziige  dieser 


Erste  Vorlesimg,  269 

Darstellung  liegen  auf  der  Hand.  Sie  lasst  zunachst  gar  keinen  Zweifel 
dariiber  aufkommen,  dass  sie  nicht  die  Dinge  an  sich  selbst  bieten  will, 
sondern  bloss  ein  inneres  geistiges  Bild  und  dass  ihr  Bestreben  bloss 
darin  besteht  dieses  geistige  Bild  zu  einer  geschickten  Bezeichnung  der 
Erscheinungen  zu  formen.  Da  die  deduktive  Methode  nicht  fortwahr- 
end  aussere  uns  aufgezwungene  Erfahrungen  mit  inneren  von  uns  will- 
kiirlich  gewahlten  Bildern  vermengt,  so  ist  es  ihr  weitaus  am  leichtesten 
diese  letzteren  klar  und  widerspruchsfrei  zu  entwickeln.  Es  ist  namlich 
eines  der  wichtigsten  Erfordernisse  dieser  Bilder,  dass  sie  vollkommen 
klar  sind,  dass  wir  niemals  in  Verlegenheit  sind,  wie  wir  sie  in  jedem 
bestimmten  Falle  formen  sollen  und  dass  wir  jedes  Mai  das  Resultat  ein- 
deutig  und  unzweifelhaft  aus  denselben  ableiten  konnen.  Gerade  diese 
Klarheit  leidet  durch  zu  friihe  Vermischung  mit  der  Erfahrung  und  wird 
bei  der  deduktiven  Darstellungsweise  am  sichersten  gewahret.  Dagegen 
tritt  bei  dieser  Darstellungsweise  besonders  die  Willkiirlichkeit  der  Bil- 
der scharf  hervor,  indem  man  mit  ganz  willkiirlichen  Gedankenconstruc- 
tionen  beginnt  und  deren  Notwendigkeit  nicht  anfangs  motivirt  sondern 
erst  hinterher  rechtfertigt.  Davon,  dass  nicht  auch  andere  Bilder  erdacht 
werden  konnten,  die  ebenso  mit  der  Erfahrung  stimmen  wlirden,  wird 
kein  Schatten  eines  Beweises  geliefert.  Es  scheint  dies  ein  Fehler  zu 
sein,  ist  aber  vielleicht  gerade  ein  Vorzug,  wenigstens  fiir  denjenigen, 
der  die  friiher  auseinandergesetzte  Ansicht  von  dem  Wesen  jeder  Theo- 
rie  hat.  Ein  wirklicher  Fehler  der  deduktiven  Methode  besteht  dagegen 
darin,  dass  der  Weg  nicht  sichtbar  wird,  auf  welchem  man  zur  Auffindung 
des  betreffenden  Bildes  gelangte.  Aber  es  ist  ja  im  Gebiete  der  Wissen- 
schaftslehre  die  Kegel,  dass  der  Zusammenhang  der  Schliisse  dann  am 
deutlichsten  hervortritt,  wenn  man  diese  moglichst  in  ihrer  natlir- 
lichen  Reihenfolge  und  ohne  Riicksicht  auf  den  oft  krummen  Weg 
auseinandersetzt,  auf  welchem  dieselben  gefunden  wurden.  Hertz 
hat  auch  im  Gebiete  der  Mechanik  in  seinem  bereits  citirten  Buche 
ein  Muster  einer  solchen  rein  deduktiven  Darstellung  gegeben.  Ich 
glaube  den  Inhalt  des  Hertz'schen  Buches  hier  als  bekannt  voraussetzen 
zu  konnen  und  mich  daher  auf  eine  ganz  kurze  Charakteristik  des- 
selben  beschranken  zu  diirfen.  Hertz  geht  von  materiellen  Punkten 
aus,  welche  er  als  reine  Gedankenbilder  betrachtet.  Auch  die  Masse 
definirt  er  ganz  unabhangig  von  aller  Erfahrung  durch  eine  Zahl,  die 
wir  uns  jedem  materiellen  Funkte  beigelegt  denken  miissen,  namlich  die 
Anzahl  der  einfachen   Massenpunkte,  welche   er  enthiilt.      Aus   diesen 


270  Ludwig  Boltzmann: 

abstrakten  Begriffen  construirt  er  eine  zuniiclist  natiirlich  Moss  wie  die 
Punkte  selbst  in  Gedanken  vorhandene  Bevvegung.  Der  Begriff  der 
Kraft  fehlt  dabei  vollstiindig.  An  ilire  Stelle  treten  gewisse  Beding- 
ungen,  welche  sicli  in  der  Form  von  Gleichungen  zwischen  den  Differen- 
zialen  der  Coordinaten  der  materiellen  Punkte  schreiben.  Diese  letzteren 
sind  nun  mit  gegebenen  Anfangsgeschwindigkeiten  ausgestattet  und 
bewegen  sich  in  jeder  folgenden  Zeit  nach  einem  sehr  einfachen  Gesetze, 
welches  sobald  die  Bedingungsgleichungen  gegeben  sind,  die  Bewegung 
fiir  alle  Zeiten  eindeutig  bestimmt.  Hertz  spriclit  es  dahin  aus,  dass  die 
Summe  der  mit  den  Massen  multiplicirten  Quadrate  der  Abweichungen 
der  materiellen  Punkte  von  der  geradlinigen,  gleichformigen  Bewegung 
fiir  jeden  Zeitmoment  ein  Minimum  sein  muss  oder  noch  kiirzer,  dass 
die  Bewegung  in  den  geradesten  Bahnen  gescliieht.  Es  hat  dieses  Gesetz 
die  grosste  Ahnlichkeit  mit  dem  Gauss'schen  Principe  des  kleinsten 
Zwanges,  ja  es  ist  gewissermassen  derjenige  spezielle  Fall,  der  eintritt, 
wenn  man  das  Gauss'sche  Princip  auf  ein  System  von  Punkten  anwen- 
det,  welche  zwar  einem  Zwange,  aber  keinerlei  sonstigen  aussern  Kraften 
unterworfen  sind. 

Ich  habe  in  meinem  Buche  welches  den  Titel  hat  "  Vorlesungen  iiber 
die  Principe  der  Mechanik"  ebenfalls  eine  rein  deduktive  Darstellung  der 
Grundprincipe  derselben  versucht,  aber  in  ganz  anderer  Weise,  weit  mehr 
an  die  gewonliche  Behandlung  der  Mechanik  ankniipfend.  Ich  gehe  wie 
Hertz  von  reinen  Gedankendiugen,  exakten  materiellen  Punkten  aus  ;  ich 
beziehe  deren  Lage  auf  ein  ebenfalls  gedachtes  rechtwinkliges  Coordina- 
tensystera  und  denke  mir  ein  geistiges  Bild  von  der  Bewegung  derselben 
zunachst  in  folgender  Weise  construirt.  Jedesmal,  wenn  sich  zwei  der- 
selben in  irgend  einer  Entfernung  r  befinden,  soil  jeder  derselben  eine 
Beschleunigung  in  der  Richtung  von  r  erfahren,  welche  eine  Function 
/(r)  dieser  Entfernung  ist,  iiber  die  spiiter  nach  Belieben  verfiigt  wer- 
den  kann.  Es  soUen  ferner  die  Beschleunigungen  beider  Punkte  in 
einem  zu  alien  Zeiten  unveranderlichen  Zahlenverhaltnisse  stehen, 
welches  das  Massenverhaltnis  der  beiden  materiellen  Punkte  definirt. 
Wie  wir  uns  die  Bewegung  aller  materiellen  Punkte  zu  denken  haben, 
das  ist  dann  eindeutig  durch  die  Angabe  bestimmt,  dass  die  wirkliche 
Beschleunigung  jedes  Punktes  die  Vectorsumme  aller  fiir  ihn  nach  der 
friiheren  Kegel  gefundenen  Beschleunigungen  ist  und  sich  zur  schon  vor- 
handenen  Geschwindigkeit  des  Punktes  ebenfalls  so  addirt  wie  Vector- 
grossen  addirt  werden.      Woher  diese  Beschleunigungen  kommen   und 


Erste  Vorlesung.  Til 

warum  ich  gerade  die  Vorschrift  gebe  sich  das  Bild  in  dieser  Weise  zii 
construiren  wird  nicht  welter  discutirt.  Es  geniigt  dass  das  Bild  ein  voU- 
kommen  klares  ist,  welches  in  geniigend  vielen  Fallen  durch  Rechnungen 
im  Detail  ausgearbeitet  werden  kann.  Dasselbe  findet  seine  Rechtfertig- 
ung  erst  darin,  dass  sich  die  Function  /(r)  in  alien  Fallen  so  bestimmen 
lasst,  dass  die  gedachte  Bewegung  der  eingebildeten  materiellen  Punkte 
in  ein  naturgetreues  Abbild  der  wirklichen  Erscheinungen  iibergetit. 

Wir  haben  durch  diese  Behandlungsweise,  welche  wir  die  rein  deduc- 
tive genannt  haben,  die  Frage  nach  dem  Wesen  der  Materie,  der  Masse, 
der  Kraft,  freilich  nicht  gelost,  aber  wir  haben  diese  Fragen  umgangen, 
indem  wir  ihre  Voranstellung  vollstandig  iiberfliissig  gemacht  haben. 
In  unserem  Gedankenschema  sind  diese  Begriffe  ganz  bestimmte  Zahlen 
und  Anweisungen  zu  geometrischen  Constructionen,  von  denen  wir  wis- 
sen,  wie  wir  sie  denken  und  ausfiihren  sollen,  damit  wir  ein  brauchbares 
Bild  der  Erscheinungswelt  erhalten.  Was  die  eigentliche  Ursache  sei, 
dass  die  Erscheinungswelt  sich  gerade  so  abspielt,  was  gewissermassen 
hinter  der  Erscheinungswelt  verborgen  ist  und  sie  treibt,  das  zu  erfor- 
schen,  betrachten  wir  nicht  als  Aufgabe  der  Naturwissenschaft.  Ob  es 
Aufgabe  einer  andern  Wissenschaft  sei  und  sein  konne,  oder  ob  wir  da 
nicht  vielleicht  bloss  nach  Analogic  mit  anderen  verniinftigen  Wortzu- 
samraenstellungen  hier  Worte  aneinandergefiigt  haben,  welche  in  diesen 
Verbindungen  keinen  klaren  Gedanken  ausdriicken,  das  kann  hier  voll- 
standig dahingestellt  bleiben.  Wir  haben  durch  diese  deductive  Methode 
ebenso  wenig  die  Frage  nach  dem  absoluten  Raume  und  der  absoluten 
Bewegung  gelost ;  allein  auch  diese  Frage  hat  keine  padagogischen 
Schwierigkeiten  mehr  ;  wir  brauchen  sie  nicht  mehr  beim  Beginne  der 
Entwickelung  der  mechanischen  Gesetze  vorzubringen,  sondern  konnen 
sie  erst  besprechen,  wenn  wir  alle  mechanischen  Gesetze  abgeleitet  haben. 
Denn  da  wir  ja  anfangs  ohnehin  nur  gedankliche  Constructionen  vor- 
flihren,  so  nimmt  sich  ein  gedachtes  Coordinatensystem  keineswegs  fremd- 
artig  unter  denselben  aus.  Es  ist  eben  eine  der  verschiedenen  uns 
verstandlichen  und  gelaufigen  Constructionsmittel  aus  denen  Avir  unser 
Gedankenbild  zusammensetzen,  nicht  mehr  und  nicht  weniger  abstract, 
als  die  materiellen  Punkte,  deren  Bewegung  relativ  gegen  das  Coordina- 
tensystem wir  uns  vorstellen  und  fiir  welche  allein  wir  zunachst  die 
Gesetze  aussprechen  und  mathematisch  formuliren.  Beim  Vergleiche 
mit  der  Erfahrung  finden  wir  dann,  dass  ein  unveranderlich  mit  dem 
Fixsternhimmel  verbundenes   Coordinatensystem  praktisch  vollkommen 


272  Ludwig  Boltzmami: 

ausreicht  um  die  Ubereinstimmung  mit  der  Erfahrung  zu  sichern.  Was 
fiir  ein  Coordiiiatensystem  wir  eiiistens  werden  zu  Grunde  legen  miissen, 
wenn  wir  einmal  die  Bewegung  der  Fixsterne  durch  mechanische  For- 
meln  ausdriicken  konnten,  diese  Frage  steht  auf  unserm  Repertoire  an 
allerletzter  Stelle  und  wir  konnen  jetzt  alle  die  Hypothesen  von  Streintz, 
Mach,  Lange  etc.  welche  eingangs  erwiihnt  wurden  mit  Leichtigkeit 
discutiren,  da  uns  alle  Gesetze  der  Mechanik  bereits  zur  Verfiigung  stehen. 
Wir  kommen  nicht  in  dieselbe  Verlegenheit  wie  friiher,  wo  wir  diese 
complicirten  Betrachtungen  der  Entwickelnng  des  Tragheitsgesetzes 
hatten  voranstellen  miissen.  Freilich  haben  wir  dafiir  bei  der  deduc- 
tiven  Methode  wieder  einen  Beweis  zu  liefern,  der  bei  den  alten  Methoden 
iiberfliissig  war.  Da  wir  bei  den  letzteren  direct  von  den  Erscheinungen 
ausgingen,  so  verstand  es  sich  von  selbst,  dass  die  Gesetze  der  Erschein- 
ungen nicht  von  der  Wahl  des  lediglich  hinzugedachten  Coordinaten- 
systems  abhangen  konnen,  und  es  musste  eben  frappiren,  dass  sich  diese 
Gesetze  anders  und  viel  complicirter  ausnehmen,  wenn  wir  ein  sich  drehen- 
des  Coordinatensystem  einfiihren.  Bei  der  deductiven  Methode  aber 
haben  wir  von  vorne  herein  dem  Coordinatensystem  im  Bilde  die  gleiche 
RoUe  angewiesen  wie  den  materiellen  Punkten.  Es  ist  ein  integrirender 
Bestandtheil  des  Bildes  und  es  kann  uns  nicht  Wunder  nehmen,  dass 
dieses  verschieden  ausfallt,  wenn  wir  das  Coordinatensystem  anders 
wahlen.  Wir  miissen  hier  im  Gegentheil  aus  dem  Bilde  selbst  den 
Beweis  liefern,  dass  dieses  sich  nicht  andert,  wenn  wir  beliebige  andere 
Coordinatensysteme  einfiihren,  so  lange  sich  diese  nicht  relativ  gegen 
einander  drehen  oder  nicht  mit  Beschleunigung  relativ  gegen  einander 
bewegen. 

Wir  woUen  nun  die  zuletzt  besprochene  Darstellungsweise  meines 
Buches  mit  der  Hertz'schen  vergleichen.  Herr  Classen  hat  meine  Dar- 
stellung  als  eine  Polemik  gegen  Hertz  aufgefasst  und  die  Sache  so  darge- 
stellt,  als  ob  ich  mir  einbildete  etwas  unbedingt  Besseres  als  Hertz 
vorgebracht  zu  haben.  Nichts  weniger  als  dies.  Ich  erkenne  die 
Vorziige  des  Hertz'schen  Bildes  unbedingt  an,  aber  nach  dem  Principe, 
dass  es  moglich  und  wiinschenswert  ist,  fiir  ein  und  dieselbe  Erscheinungs- 
gruppe  mehrere  Bilder  aufzustellen,  glaube  ich,  dass  niein  Bild  neben  dem 
Hertz'schen  noch  seine  Bedeutung  hat,  indem  es  gewisse  Vorziige  auf- 
weist,  welche  dem  Hertz'schen  fehlen.  Die  Principe  der  Mechanik, 
welche  Hertz  aufstellt,  sind  von  aussererordentlicher  Einfachheit  und 
Schonheit.      Sie  sind  natiirlich  nicht  vollstandig  frei  von  Willkiirlich- 


Erste  Vorlesuiig.  273 

keit,  aber  ich  mochte  sagen  die  Willklirliclikeit  ist  auf  ein  Minimum 
beschriinkt.  Das  von  Hertz  unabhiingig  von  der  Erfalirung  construirte 
Bild  hat  eine  gewisse  innere  Vollendung  und  Evidenz.  Es  enthalt  an 
sich  nur  wenig  willklirliche  Elemente.  Hingegen  steht  offenbar  mein 
Bild  weit  zuriick.  Letzteres  enthalt  weit  mehr  Ziige,  welche  den  Stempel 
davon  an  sich  tragen,  dass  sie  nicht  durch  eine  innere  Notwendigkeit 
bestimmt  sind,  sondern  bloss  eingefiigt  wurden,  um  hinterher  dann  eben 
die  Ubereinstimmung  mit  den  Erfalirung  zu  ermoglichen.  Es  enthalt 
audi  eine  ganz  willklirliche  Function  und  von  den  vielen  Bildern, 
welche  entstehen,  wenn  dieser  Function  alle  moglichen  Formen  er- 
theilt  werden,  entsprechen  nur  ganz  wenige  wirklichen  Vorgangen, 
wahrend  man  beim  Hertz'schen  Bilde  sofort  sieht,  dass  wenn  iiberhaupt 
einige,  so  doch  jedenfalls  nur  wenige  andere  Bilder  moglich  sein 
konnen,  welche  sich  einer  gleichen  Einfachheit  und  inneren  Vollendung 
erfreuen,  so  weckt  mein  Bild  sofort  die  Idee,  dass  es  wohl  noch  so 
manche  andere  geben  mag,  welche  die  Erscheinungen  mit  gleicher  Voll- 
kommenheit  darstellen.  Trotzdem  giebt  es  aber  wieder  Punkte,  in 
denen  mein  Bild  dem  Hertz'schen  iiberlegen  ist.  Hertz  kann  zwar  einige 
Erscheinungen  in  directer  Weise,  aus  seinem  Bilde  erklaren,  oder  wie 
wir  lieber  sagen  woUen,  mittelst  desselben  darstellen,  so  die  Bewegung 
eines  materiellen  Punktes  auf  eitier  vorgeschriebenen  Flache  oder  Kurve 
oder  die  Drehung  eines  starren  Korpers  um  einen  fixen  Punkt,  beides 
wolgemerkt,  so  lange  keine  fremdartigen  aussern  Krafte  vorhanden  sind. 
Man  stosst  aber  sofort  auf  Schwierigkeiten,  sobald  man  die  gewohnlich- 
sten  in  der  taglichen  Erfahrung  vorkommenden  Vorgange  darstellen  will, 
bei  denen  Krafte  wirken.  Betrachten  wir  zunachst  eine  der  allgemeinsten 
und  wichtigsten  Naturkrafte,  die  Gravitation.  Als  Fernkraft  diirfen  wir 
dieselbe  vom  Hertz'schen  Standpunkte  natiirlich  nicht  auffassen.  Es  sind 
nun  zwar  zahlreiche  Versuche  gemacht  worden,  sie  durch  Wirkung  eines 
Mediums  mechanich  zu  erklaren.  AUein  es  ist  bekannt,  dass  keiner  der- 
selben  zu  einem  recht  bestimmten,  entscheidenden  Resultate  gefiihrt  hat. 
Einer  der  bekanntesten  ist  die  schon  von  Lesage  aufgestellte,  spater  von 
Lord  Kelvin,  Isenkrahe  und  andern  wieder  aufgenommene  Theorie  der 
Molekularstosse.  Dieselbe  ist  abgesehen  davon,  dass  ihre  exacte  Durch- 
fiihrbarkeit,  noch  immer  zweifelhaft,  ist  fiir  die  Hertz'sche  Theorie 
unbrauchbar,  well  schon  die  Erklarung  eines  einzigen  elastischen  Stosses 
aus  derselben  Schwierigkeiten  bereitet,  wie  wir  sogleich  sehen  werden. 
Man  miisste  also  erst  eine  ganz  neue  Theorie  schaffen,  die  Gravitations- 


274  Ludwig  Boltzmann: 

wirkung  etwa  durch  Wirbel,  Pulsationen  oder  Ahnliches  erklaren, 
wobei  die  Theilchen  des  betreffeiiden  Mediums  ebenfalls  nicht  durch 
Kriifte  im  alten  Sinne,  sondern  bloss  durch  Bedingungsgleichungen  von 
der  Form,  wie  sie  Hertz  aufstellt  verkniipft  sein  diirften.  Selbst,  wenn 
dies  gelingen  sollte,  so  hiesse  dies  doch  zu  einem  ganz  willkiirlichen  Bilde 
greifen,  welches  hochst  wahrscheinlich  im  Verlaufe  der  Zeit  durch  ein 
ganz  anderes  ersetzt  werden  miisste.  Der  Vorwurf,  welchen  Hertz  gegen 
die  alte  Mechanik  erhebt,  dass  sie  ein  viel  zu  weites  Bild  gibt,  indem  von 
alien  moglichen  die  Kraft  darstellenden  Functionen  /(/•)  nur  ganz  wenige 
eine  praktische  Verwendung  haben  lasst  sich  in  verstarktem  Masse  gegen 
sein  eigenes  Bild  kehren,  sobald  man  dasselbe  auf  bestimmte  Fiille  anwen- 
den  will.  Schon  bei  der  Anwendung  auf  die  Gravitation  muss  man  aus 
alien  moglichen  Medien,  welche  Fernwirkung  vermitteln  konnten  irgend 
ein  bestimmtes  auswahlen,  worin  wohl  noch  mehr  Unbestimmtheit  und 
Willkiirlichkeit  liegt  als  in  der  Wahl  gewisser  Functionen  /(r). 

Die  elektrischen  und  magnetischen  Krafte  hat  bekanntlich  Maxwell 
in  seinen  ersten  Arbeiten  mit  Erfolg  durch  die  Wirkung  eines  Mediums 
erkltirt.  AUein  abgesehen  davon,  dass  dieses  Medium  einen  hochst 
complicirten  Bau  hatte  und  von  Eigenschaften  strotzte,  die  den  Stempel 
der  Willkiirlichkeit  und  eines  rein  provisorischen  Charakters  an  sich 
trugen,  so  ware  es  flir  Hertz  wieder  nicht  einmal  brauchbar,  indem  seine 
Theile  ebenfalls  von  Kraften  im  alten  Sinne  der  Mechanik  zusammen- 
gehalten  werden.  Ja  auch  die  Eigenschaften  der  elastischen,  tropf- 
barfliissigen  und  gasformigen  Korper  miissten  durch  neue  Bilder  ersetzt 
werden,  da  die  bisherigen  alle  auf  die  Annahme  von  zwischen  den  Theil- 
chen wirkenden  Kraften  gegriindet  sind.  Man  hat  also  nur  folgende 
Walil,  entweder  man  lasst  die  Natur  des  Mechanismus,  welcher  die 
Gravitation,  die  elektrischen  und  magnetischen  Erscheinungen  erzeugen 
soil,  unbestimmt  und  willkiirlich.  Dadurch  entsteht  eine  unertragliche 
Unanschaulichkeit,  indem  man  genothigt  ist  immer  mit  Gleichungen  zu 
operiren,  von  denen  man  nur  einige  ganz  allgemeine  Eigenschaften  kennt, 
deren  spezielle  Form  aber  vollstandig  unbekannt  ist,  oder  man  bemiiht 
sich  einen  bestimmten  Mechanismus  zu  walilen,  wodurch  man  dann  wieder 
in  eben  so  viele  Willkiirlichkeiten  als  Schwierigkeiten  verwickelt  wird. 

Doch  ich  will  noch  an  einem  viel  einfacheren  Beispiele  die  Schwierig- 
keiten zeigen,  auf  welche  die  Anwendung  des  Hertz'schen  Fundamental- 
gesetzes  schon  in  den  trivialsten  Fiillen  stosst. 

Es  seien  drei  Massen  Wj,  u  und  Wg  mit  der  Bedingung  gegeben,  dass 


Erste  Vorlesung.  275 

sowohl  die  Entfernung  Wj  u  als  auch  die  u  m^  stets  gleich  derselben 
Grosse  a  sein  soil.  Lassen  wir  dann  die  Masse  u  immer  kleiner  werden, 
so  erhalten  wir  einen  voUkommen  dem  Geiste  der  Hertz'schen  Meclianik 
entsprechenden  Fall,  der  uns  ein  getreues  Bild  des  folgenden  Natur- 
vorgangs  gibt.  In  einer  elastischen  Hohlkugel  von  der  Masse  m^  bewege 
sich  eine  kleine  elastische  VoUkugel ;  die  Differenz  der  Radien  sei  2  a. 
Wir  haben  also  hier  ein  Beispiel  eines  und  desselben  Naturvorganges, 
welcher  auf  zwei  ganz  verschiedenen  Wegen  erklart  werden  kann,  eines- 
theils  aus  der  Molekulartheorie,  anderstheils  nach  der  von  Hertz 
angegebenen  Methode.  Aber  so  verhalten  sich  nicht  alle  Vorgiinge. 
Schon  der  ganz  triviale  Fall  des  Stosses  zweier  elastischen  Vollkugeln 
ist  aus  dem  Hertz'schen  Schema  nur  durch  zeimlich  willkiirlich  gewahlte 
Mechanismen  oder  complicirte  Annahmen  iiber  ein  Zwischenmedium 
ableitbar,  da  ja  die  Hertz'sche  Methode  Ungleichungen  ausschliesst.  Es 
fiihrt  also  die  Hertz'sche  Methode  schon  in  den  einfachsten  Fallen  zu 
den  grossten  Complicationen. 

Ich  betone  hier  nochmals,  dass  diese  Ausfiihrungen  keineswegs  den 
Zweck  haben  sollen,  den  hohen  Wert  des  Hertz'schen  Bildes  zu  leugnen, 
welcher  in  der  logischen  Einfachheit  seiner  Grundprincipien  besteht. 
Es  ware  ja  moglich,  dass  man  in  ferner  Zukunft  einmal  alle  Wirkungen 
durch  Medien  erkliiren  kann,  deren  Eigenschaften  nicht  phantastisch 
gewahlt,  sondern  durch  die  Natur  der  Sache  in  nahe  liegender  und  un- 
zweideutiger  Weise  geboten  werden.  Es  ware  moglich,  dass  die  Theil- 
chen  dieser  Medien  nicht  Krafte  im  alten  mechanischen  Sinne  aufeinander 
ausiiben,  sondern  dass  man  mit  Bedingungsgleichungen  im  Hertz'schen 
Sinne  zwischen  den  Coordinaten  der  Elementartheilchen  ausreichen 
wiirde.  Von  diesem  Augenblicke  an  hatte  die  Hertz'sche  Mechanik 
in  unzweifelhafter  Weise  den  Sieg  davongetragen  und  alle  andern  Dar- 
stellungen  hatten  nur  mehr  historisches  Interesse.  Ob  man  das  einstige 
Eintreffen  eines  solchen  Zeitmomentes  fiir  wahrscheinlich  hiilt  oder  nicht 
ist  natiirlich  eine  reine  Geschmackssache.  Bewiesen  ist  nicht  einmal  die 
Moglichkeit  einer  derartigen  Entwicklung  unserer  Erkentnis.  Wir  wer- 
den daher  auf  unserem  gegenwiirtigem  Standpunkte  zu  jenem  Ideale  mit 
Bewunderung  aufblicken,  auch  das  Unserige  zur  Beforderung  der  An- 
naherung  an  dasselbe  beitragen.  Aber  einstweilen  werden  wir  solche 
einfache  und  unmittelbar  brauchbare  Bilder,  welche  sich  jetzt  schon 
ins  Detail  durchfiihren  lassen  neben  den  Hertz'schen  nicht  entbehren 
konnen. 


276  Ludwig  Boltzmann: 

ZWEITE   VORLESUNG. 

Icli  habe  in  der  vorigen  Vorlesung  zwei  Bilder  der  mechanischen  Er- 
scheinungen  besprochen,  welche  beide  rein  deductiv  sind,  das  Hertz'sche 
und  das  in  meinem  Buche  iiber  Mechanik  dargestellte.  Das  letztere  un- 
tersclieidet  sich  dem  Wesen  nach  nicht  von  den  alteren  Theorien  der 
Mechanik.  Ich  bemiihte  mich  nur  diese  durch  eine  moglichst  conse- 
quente  Darstellung  gegen  etwaige  Einwiirfe  besonders  gegen  die  Be- 
denken  zu  sichern,  welche  Hertz  in  der  Vorrede  seines  Buches  gegen 
die  altere  Mechanik  erhebt.  Gerade  zu  diesem  Zwecke  schien  sich  die 
rein  deductive  Darstellung  am  besten  zu  eignen,  well  sie  das  Bild  ganz 
unabhangig  von  den  Thatsachen  in  moglichster  Klarheit  zu  entwickeln 
erlaubt.  Man  konnte  jedoch  das  Bild  auch  nach  der  entgegengesetzten 
Methode  entwickeln,  indem  man  unmittelbar  von  den  Thatsachen  aus- 
ginge,  wie  sie  sich  der  unbefangenen  Beobachtung  bieten,  aus  diesen  That- 
sachen die  Bilder  erst  allmalig  entstehen  liesse  und  jede  Abstraction  erst 
dann  einfiihrte,  wenn  sie  auf  keine  Weise  mehr  abgewiesen  werden  kann. 
Diese  letztere  Darstellung  woUen  wir  die  inductive  nennen.  Dieselbe 
hat  der  deductiven  gegeniiber  den  Nachtheil,  dass  die  Bilder  von  Anfang 
an  nicht  so  rein  hervortreten,  daher  ihre  innere  Consequenz  nicht  so  klar 
zu  iibersehen  ist.  AUein  sie  hat  auch  wieder  den  Vortheil,  dass' sie  an 
Stelle  der  lange  Zeit  hindurch  rein  abstracten  von  der  Wirklichkeit 
abgekehrten  Darstellungsweise  der  deduktiven  Methode  rein  an  das 
unmittelbar  Gegebene  und  Gelaufige  ankniipfende  setzt  und  moglichst 
klar  erkennen  lasst,  wie  die  abstracten  Bilder  entstanden  sind  und 
warum  wir  gerade  zu  diesen  Bildern  unsere  Zuflucht  nehmen.  Um  die 
Vorziige  und  Nachtheile  der  deductiven  Methode  mit  der  inductiven  zu 
vergleichen,  ware  es  nicht  ganz  zweckmassig  die  im  vorigen  Vortrage 
geschilderte  Methode  mit  den  alteren  in  der  Mechanik  liblichen  Darstel- 
lungsweisen  zu  vergleichen,  da  die  letzteren  beide  Methoden  vermischen 
und  dadurch  wie  mir  scheint  die  Klarheit  beeintrachtigen.  So  werden  in 
der  Kegel  sehr  bald  abstracte  Begriffe,  wie  der  des  materiellen  Punktes, 
der  Masse  etc.,  eingef  iihrt,  diese  aber  nicht,  wie  von  uns  in  der  vorigen  Vor- 
lesung als  rein  gedankliche  Werkzeuge  aufgefasst.  Es  werden  vielmehr 
davon  mehr  oder  minder  unbestimmte  und  nichts  sagende  Definitionen 
gegeben.  So  wird  der  materielle  Punkt  als  ein  Korper  definirt,  welcher 
so  klein  ist,  dass  seine  Ausdehnung  vernachlassigt  werden  kann.  Man 
meint  damit  etwa,  dass  seine  Tragheitsmomente  beziiglich  einer  durch 


Zweite  Vorlesung.  277 

seinen  Schwerpunkt  gehenden  Axe   gegenliber    denen    beziiglich   einer 

andern  Axe  verschwinden,  die  sich  davon  in  einer  Entfernung  befindet, 

die  von  der  Grossenordnung  der  Entfernungen  ist,  welche  bei  unsern 

Experimenten  fiir  gewohnlich  vorkommen  oder  Ahnliches.     Da  aber  der 

Begriff  des  Tragheitsmomentes,  Schwerpunkts  etc.  noch  niclit  entwickelt 

worden  ist,  so  wiisste  ich  niclit  was  man  sich  unter  einem  Korper,  an  dem 

eine  der  wichtigsten  Eigenschaften,  namlich  die  Ausdehnung  vernach- 

lassigt  werden  kann,  denken  soil.      Die  Masse  wird  oft  definirt  durch 

die  Wirkung  einer  und  derselben  Kraft  auf  verschiedene  Korper,  aber 

wie  soil  man  constatiren,  dass  die   Kraft  dieselbe  ist,  wenn  sie  einmal 

auf  diesen  einmal  auf  jenen  Korper  wirkt?     Es  wird  daher  das  Beste 

sein,  wenn  wir  versuchen  noch  eine  neue  rein  inductive  Darstellung  der 

Grundprincipien  der  Mechanik  wenigstens  mit  einigen  Strichen  zu  ski- 

ziren.     Wir  bleiben  dabei  unserm  Princip  treu,  dass  wir  vorlaufig  keines- 

wegs  eine  einzige  beste  Darstellung  der  Wissenschaft  erstreben,  sondern 

dass  wir  es  fiir   niitzlich  halten  moglichst  viele  verschiedene  Darstel- 

lungen  zu  versuchen,  von  denen  jede  ihre  besondern  Vorziige,  freilich 

auch  wieder  jede  ihre  Mangel  hat.     Das  Hauptaugenmerk  wird  dabei 

wieder  darauf  zu  richten  sein  alle  Inconsequenzen  und  logischen  Fehler 

zu  vermeiden,  keinen  Begriff  oder  keine  Annahme  stillschweigend  einzu- 

schmuggeln,  sondern  uns  aller  gemachten  Hypothesen  mit  moglichster 

Klarheit  bewusst  zu  werden.     Es  versteht  sich  von  selbst,  dass  ich  hier 

bei   der  Kiirze  der  mir  zur  Verfiigung  stehenden  Zeit  nicht  die  ganze 

Mechanik  erschopfend  darstellen  kann.     Ich  werde  nur  versuchen  einige 

Andeutungen  zu  geben.     Es  ware  wol  auch  kaum  moglich  eine  so  schwie- 

rige  Aufgabe  auf  einmal  ganz  der  Losung  zuzufiihren.     Viel  wird  an 

dem  ersten  Versuche  noch  mangelhaft  sein  und  erst  allmalig  werden  sich 

die  Begriffe  sichten  und  die  Darstellungsweisen  vervollkommnen.      Wir 

werden  da  gerade  denjenigen  Weg  einschlagen  miissen,  der  dem  in  der 

vorigen  Vorlesung  geschilderten  und  in  meinem  Buche  liber  Mechanik 

verfolgten,  direct  entgegengesetzt  ist.     Die  abstracten  Begriffe  des  mate- 

riellen  Punktes,  der  Masse,  Kraft  etc.,  von  denen  wir  dort  ausgingen, 

werden  wir  nun  zwar  auch  nicht  ganz  vermeiden  konnen ;  denn  sie  sind 

einmal  die  Grundpfeiler,  auf  welche  die  Mechanik  aufgebaut  ist.     Aber 

wir  werden  sie  jetzt  so  spiit  als  moglich  einfiihren  und  wiihrend  wir  sie 

friiher  postulirten,  werden  wir  jetzt  moglichst  an  die  Erfahrung  anknlip- 

fen  und  unsere  Resultate  daraus  zu  deduciren  suchen.     Daher  sind  jetzt 

auch  diejenigen  Gesetze,  welche  friiher  die  einfachsten  schienen,  nicht 


278  Ludwig  Boltzmann: 

voranzustellen,  wie  z.  B.  das  TrJiglieitsgesetz.  Dieses  wird  gewohnlich 
dahin  ausgesprochen,  dass  ein  materieller  Punkt,  welcher  jedem  iiusseren 
Einfiusse  entzogen  ist,  sich  geradlinig  und  gleichformig  bewegt.  Abge- 
sehen  von  der  Schwierigkeit,  die  im  Begriffe  des  materiellen  Punktes 
liegt,  konnen  wir  nun  aber  keinen  Korper  so  weit  von  alien  iibrigen 
entfernen,  dass  er  jedem  Einfiusse  entzogen  ist  und  ware  dies  moglich, 
so  konnten  wir  seine  Bewegung  nicht  mehr  beobacliten,  geschweige  denn 
deren  Geradlinigkeit  und  Gleicliformigkeit  constatiren.  Wenn  man  aber 
das  Tragheitsgesetz  an  Korpern  verificiren  will,  an  denen  sich  alle  darauf 
wirkenden  Kriifte  das  Gleichgewiclit  lialten,  so  miisste  man  die  gesammte 
Lehre  vom  Gleichgewichte  schon  vorausschicken.  Man  pflegt  also  in 
der  gewohnlichen  Darstellung  Abstractionen  und  Thatsaclien  vielfach 
zu  vermischen,  was  zu  vermeiden  eben  im  folgenden  unsere  Hauptauf- 
gabe  sein  soil,  da  wir  uns  vornehmen  streng  von  reinen  Erfahrungsthat- 
sachen  auszugehen. 

Die  erste  Unbequemlichkeit,  die  uns  hiebei  entgegentritt  ist  folgende: 
Friiher  batten  wir  es  bei  Aufstellung  der  ersten  Grundprincipien  mit  rein 
Gedacbtem  zu  thun,  das  wir  in  unserer  Idee  formen  kdnnen,  wie  wir 
woUen,  und  wovon  wir  verlangen  konnen,  dass  es  immer  exact  unseren 
Anf order ungen  entspriclit,  jetzt  dagegen  woUen  wir  von  den  direct 
beobachteten  Erscheinungen  ausgehen,  welche  immer  sehr  zusammenge- 
setzt  und  complicirt  sind.  WoUen  wir  daraus  Grundgesetze  gewinnen, 
so  miissen  wir  die  Erscheinungen  immer  generalisiren  und  idealisiren,  so 
dass  wir  schon  nicht  mehr  ganz  exacte  Thatsachen  vor  uns  haben  son- 
dern  Vorgange,  welche  in  der  Natur  immer  nur  mit  grosserer  oder  gerin- 
gerer  Annilherung  realisirt  sind.  Wir  konnen  es  daher  auch  nicht  ganz 
vermeiden  Vorstellungen  und  Thatsachen  zu  vermengen  aber  wir  suchen 
dies  wenigstens  auf  das  kleinste  Mass  zuriick  zu  fiihren  und  bestreben  uns 
es  nicht  versteckt  zu  thun,  sondern  wo  wir  dazu  gezwungen  sind  uns 
dessen  klar  bewusst  zu  bleiben. 

Die  Erscheinungen,  welche  uns  gegeben  sind,  haben  eine  ausserordent- 
lich  verschiedene  Natur.  Die  einfachsten  bestehen  in  Ortsveranderungen 
eines  Korpers,  welcher  dabei  weder  seine  Gestalt  noch  seine  sonstigen 
Eigenschaften  irgendwie  zu  veriindern  scheint.  Schon  diese  einfache 
Erscheinung  ist  in  gewisser  Beziehung  eine  idealisirte.  In  den  wenigsten 
Fallen  iindert  der  Korper  seine  Gestalt  absolut  gar  nicht ;  ja  alle,  selbst 
die  unveriinderlichsten  Korper  konnen  durch  sehr  starke  Kriifte  zer- 
brechen,  durch  Hitze,  chemische  Wirkungen,  zu  volliger  Veranderung  ihrer 


Zweite  Vorlesmig.  279 

Eigenschaften  veranlasst  werden.  Aber  es  gibt  sehr  viele  Korper,  die  doch 
ihre  Gestalt  wiihrend  der  mannigfaltigsten  Bewegungen  durch  lange  Zeit 
nicht  bemerkbar  andern.  Wir  nennen  sie  feste  Korper  und  bilden  uns 
das  Ideal  eines  absolut  unveranderlichen  Korpers,  welchen  wir  einen 
starren  nennen.  Andere  Korper,  die  Fliissigkeiten  andern  wiihrend  ihrer 
Bewegung  ihre  Gestalt  in  der  mannigfaltigsten  Weise,  entweder  bei 
(natiirlich  wieder  nur  angenaliert)  gleich  bleibendem  Volumen,  (die  tropf- 
baren  Fliissigkeiten)  oder  unter  steter  sehr  merkbarer  Anderung  des  Vol- 
umens,  (die  Gase).  Man  kann  die  letzteren  Erscheinungen  auf  die  erstern 
zuriickfiihren,  indem  man  annimmt,  dass  die  Fliissigkeiten  aus  sehr  vielen 
sehr  kleinen  Theilchen  bestehen,  deren  Bewegung  unabhangig  von  ein- 
ander,  die  Gestaltanderung  hervorruft.  Andert  sich  dabei  die  durch- 
schnittliche  Entfernung  je  zweier  Nachbartheilcheu,  so  ist  dieselbe  auch 
mit  Volumanderung  verkniipft.  Es  ist  nun  die  Frage,  soil  man  sich  die 
Anzahl  dieser  Theilchen  mathematisch  unendlich  oder  bloss  sehr  gross 
aber  endlich  denken.  Viele  Erfahrungsthatsachen  deuten  darauf  hin, 
dass  die  letztere  Annahme  gemacht  werden  muss,  welche  auch  philoso- 
phisch  die  befriedigendere  ist.  Aber  da  eine  unzweifelhafte  experi- 
mentelle  Entscheidung  bisher  nicht  erfolgt  ist,  so  wollen  wir  getreu  den 
Principien,  nach  denen  wir  jetzt  vorzugehn  beabsichtigen,  diese  Frage 
voUstandig  in  suspenso  lassen. 

Alle  Ortsveranderung  heissen  Bewegungen.  Die  Lehre  von  den 
Bewegungserscheinungen  ist  die  Mechanik,  welche  sich  in  die  Geo-,  Hydro- 
und  Aero-mechanik  abtheilt,  je  nachdem  man  es  mit  der  Bewegung 
fester,  tropfbarer  oder  gasformiger  Korper  zu  thun  hat.  Die  Mechanik 
umfasst  ihrer  Definition  gemass  auch  die  Bedingungen,  unter  denen  sich 
ein  Korper  garnicht  bewegt. 

Es  gibt  noch  vielerlei  Erscheinungen  der  Schall,  die  Warme,  das 
Licht,  die  elektrischen  und  magnetischen  Erscheinungen,  die  ganzliche 
Anderung  der  Eigenschaften  von  Korpern  bei  chemischen  Prozessen,  die 
Geruchs-,  Geschmackerscheinungen  etc.  Letztere  sind  wahrscheinlich 
nur  spezielle  Falle  von  Verdampfungs-  oder  chemischen  Erscheinungen, 
und  daher  fiir  die  Physik  von  geringerer  Wichtigkeit,  welche  ja  die 
Action  auf  die  Nerven  und  die  Fortleitung  durch  dieselben  bis  zum 
Bewusstwerden  der  Physiologic  und  Psychologic  iiberlasst.  Aber  sie 
miissen  hier  doch  ebenfalls  erwahnt  werden. 

Es  ist  unzweifelhaft  nachgewiesen,  dass  den  Schallerscheinungen 
Bewegungen  der  Korper  zu  Grunde  liegen.      Naturgemass  suchte  man 


280  Ludwig  Boltzmann: 

auch  Licht,  ElektricitJit  und  Magnetismus,  so  wie  die  chemischen 
Ersclieinungen  durch  Bewegungserscheinungen  gewisser  hypothetischer 
Medien  oder  hypothetischer  kleinster  Theile  zu  erklaren  und  bis  vor 
Kurzem  war  wohl  jeder  Physiker  iiberzeugt,  dass  hiemit  dem  Wesen  nach 
die  eigentliche  Aufgabe  der  Physik  ausgesprochen  sei.  Erst  vor  wenigen 
Decennien  wurde  unwiderleglich  nachgewiesen,  dass  die  besonders  in 
Deutschland  friiher  allgemein  verbreitete  Theorie  der  elektrischen  und 
magnetischen  Fluide  mit  den  Thatsachen  nicht  in  Ubereinstimmung 
gebracht  werden  kann.  Man  wurde  nun  vorsichtiger,  man  suchte  zwar 
die  elektrischen  und  magnetischen  Erscheinungen  zuuiichst  wieder  durch 
mechanische  Wirkung  eines  Mediums  zu  erklaren,  allein  da  man  hiebei 
nicht  zu  einem  bestimmten  eindeutigen  Erfolge  gelangte,  so  neigen  in 
neuester  Zeit  manche  Physiker  zur  Ansicht,  dass  es  wol  ein  iibereilter 
Schluss  sei,  dass  sich  alle  Erscheinungen  durch  Bewegungsphanomene 
miissten  erklaren  lassen  oder  in  unsere  Ausdrucksweise  iibertragen,  dass 
es  vielleicht  gar  nicht  moglich  sei  durch  die  Bilder  von  Ortsverander- 
ungen  von  Punkten  und  Korpertheilen  allein  sich  ein  ausreichendes 
Bild  der  Erscheinungen  zu  verschaffen ;  dass  man  dazu  noch  qualitativ 
verschiedene  Bilder  wie  dielektrische  und  magnetische  Polarisationen, 
chemische  Zustande  oder  anderes  dazunehmen  miisse.  Es  wiirde 
dadurch  die  Einheit  der  Naturwissenschaft  ausserordentlich  leiden,  da 
man  auf  keinen  Fall  die  alten  einfachen  Bilder  vermeiden  konnte  und 
uns  noch  eine  Menge  fremdartiger  dazu  einfiihren  miisste.  Es  wiirde 
dann  auch  die  Bedeutung  der  Mechanik  als  Grundlage  der  gesammten 
Naturwissenschaft,  auf  welcher  alle  iibrigen  Theorien  derselben  beruhen, 
in  Frage  gestellt.  Aber  immer  hatte  noch  die  Mechanik  als  die  Lehre 
der  einfachsten  Erscheinungen,  ohne  die  irgend  welche  andere  nicht 
denkbar  sind,  alien  andern  physikalischen  Theorien  voranzugehn.  Wenn 
man  daher  auch  einerseits  nicht  leugnen  kann,  dass  der  Beweis  der 
mechanischen  Erklarbarkeit  aller  Naturerscheinungen  noch  nicht  geliefert 
ist,  so  ist  doch  sicher  ebenso  wenig  ein  Beweis  geliefert,  dass  gewisse 
Naturerscheinungen  nicht  durch  mechanische  Bilder  erkliirbar  sein 
konnten,  und  man  kann  hochstens  die  Ansicht  aussprechen,  dass  bei  gewis- 
sen  Naturerscheinungen  der  Versuch  einer  mechanischen  Erkliirung  heute 
noch  zu  friih  kommt.  Die  allgemeine  Frage  an  sich  kann  erst  nach 
Jahrhunderten  entschieden  oder  wenigstens  in  ein  wesentlich  neues  Licht 
gerilckt  und  geklart  werden.  Wir  wollen  uns  daher  mit  der  Discussion 
des  "Fiir"  oder  "Wider"  hier  nicht  aufhalten,  sondern  kehren  zur  Beweg- 


Zweite  Vorlesung.  281 

ung  eines  festen  Korpers  K  zuriick,  den  wir  sogleich  idealisiren,  indera 
wir  ilin  als  absolut  starr  denken.  Wir  fassen  denselben  nicht  etwa  als 
eiuen  materiellen  Punkt,  sondern  als  einen  erfahrungsmassig  gegebenen, 
wenigstens  dem  Scheine  nach  continuirlicli  ausgedehnten  Korper  auf. 
Wir  miissen  freilich  wieder  sogleich  mit  einer  Abstraction  einsetzen  ;  wir 
konnen  die  Bewegung  des  Korpers  nicht  auf  einmal  als  Ganzes  erfassen, 
da  er  ja  (wenigstens  fiir  uns  scheinbar)  aus  unendlich  vielen  Theilen 
besteht.  Wir  konnen  bloss  die  Bewegung  einzelner  Punkte  desselben 
klar  mit  dem  Auge  und  Gedanken  verfolgen.  Wir  wollen  daher  sehr 
kleine  Stellen  desselben  A^  B^  C,  .  .  .  mit  feinen  selbstverstandlich 
ebenfalls  starr  mit  dem  Korper  verbundenen  Marken  bezeichnen  etwa 
mit  feinen  Farbepunkten,  Mehlstaubchen  oder  durch  die  Kreuzung  zweier 
feiner  Linien  etc.  Wenn  wir  eine  ausserordentlich  enge  Hohlung  in  den 
Korper  bohren,  so  konnen  wir  auch  Punkte  im  Innern  desselben  wirklich 
bezeichnen  und  wir  konnen  es  auch  ohne  die  Hohlung  in  Gedanken, 
wenn  wir  uns  etwa  einen  geometrisch  ahnlichen  hohlen  oder  durchsichti- 
gen  oder  sonst  an  dieser  Stelle  zuganglichen  Korper  vorstellen.  Es  ist 
freilich  schon  wieder  eine  Idealisirung,  wenn  wir  uns  diese  bezeichneten 
Stellen  als  mathematische  Punkte  denken  ;  allein  wir  bleiben  doch  dem 
thatsachlich  Realen  viel  naher,  wenn  wir  die  Bewegung  des  ausgedehnten 
Korpers  durch  solche  Punkte  beschreiben  und  an  erster  Stelle  einfache 
Gesetze  fiir  die  Mechanik  ausgedehnter  Korper  zu  gewinnen  suchen,  als 
wenn  wir  direkt  mit  den  Gesetzen  fiir  die  Bewegung  einzelner  materieller 
Punkte  beginnen.  Wir  konnen  jetzt  genauer  beschreiben,  was  es  heisst, 
wenn  wir  sagen  die  Gestalt  eines  Korpers  iindert  sich  wahrend  seiner 
Bewegung  nicht.  Wir  konnen  durch  Anlegen  eines  Massstabes  oder 
zweier  Zirkelspitzen,  die  wir  dann  auf  einen  Massstab  iibertragen  die  Ent- 
fernung  je  zweier  beliebiger  Punkte  des  Korpers  K d.  h.  zweier  beliebiger 
hervorgehobener  Marken  auf  demselben  messen.  Wenn  dieselbe  fiir  alle 
Punktepaare  zu  alien  Zeiten  unveriindert  bleibt,  so  sagen  wir  die  Gestalt 
des  Korpers  ist  unveriinderlich.  Fiir  die  Unveriinderlichkeit  des  Mass- 
stabes oder  Zirkels  haben  wir  freilich  keine  objective  Garantie,  sondern 
nur  die  empirische,  dass  uns  dieselben  an  alien  Korpern,  welche  schon  dem 
Augenscheine  nach  ihre  Gestalt  nicht  andern,  die  richtige  Anzeige  liefern. 
Wenn  alle  festen  Korper  in  gleicher  Weise  ihre  Dimensionen  mit  der 
Zeit  andern  wiirden,  so  konnten  wir  dies  natiirlich  nicht  bemerken. 
Wir  haben  auch  durchaus  nicht  die  Absicht  zu  erkliiren,  wieso  es  feste 
Korper  gibt,  wieso  wir  die    Entfernungen  der  damit  fest  verbundnen 


282  Liidivig  Boltzmann: 

INIarken  messen  konnen.  Wir  nehmen  dies  als  Erfahrungsthatsachen  bin, 
nur  die  Gesetze  der  Veriinderung  der  Entfenmngen  der  Marken  ver- 
schiedener  Korper  oder  auch  desselben  Korpers  falls  dieser  nicht  starr  ist, 
woUen  wir  durch  unsere  Vorstellungsbilder  darstellen. 

Vorbedingung  jeder  wissenschaftlichen  Erkenntniss  ist  das  Princip  der 
eindeutigen  Bestimmtheit  der  Naturvorgiinge,  auf  die  Mechanik  ange- 
wandt  der  eindeutigen  Bestimmtheit  aller  Bewegungen.  Dasselbe  sagt 
aus,  dass  die  Bewegungen  der  Korper  nicht  rein  zufallig  bald  so,  bald 
anders  vor  sich  gehn,  sondern  dass  sie  durch  die  Umstande,  unter  denen 
sich  der  Korper  befindet,  eindeutig  bestimmt  sind.  Wenn  jeder  Korper 
sich  wie  er  woUte  bewegte,  wenn  unter  gleichen  Umstanden  bald  diese, 
bald  jene  Bewegung  je  nach  Zufall  erfolgte,  so  konnten  wir  dem  Verlaufe 
der  Erscheinungen  nur  neugierig  zusehen  nicht  ihn  erforschen.  Auch 
hierin  liegt  wieder  eine  Unbestimmtheit,  die  Umstande,  unter  denen  die 
Bewegung  irgend  eines  Korpers  vor  sich  geht,  urafassen  streng  genom- 
men  das  ganze  Universum.  Dasselbe  ist  nie  zweimal  im  selben  Zustande. 
Wir  mlissen  also  unsere  Bedingungen  dahin  reduziren,  dass  immer  die- 
selbe  Bewegung  erfolgt,  wenn  die  unmittelbare  Umgebung  sich  in  dem- 
selben  Zustande  befindet.  Wir  sind  hier  bei  der  inductiven  Methode 
wieder  in  einer  weit  ungiinstigeren  Lage  als  bei  der  Deductiven.  Denn 
da  wir  bei  der  letztern  mit  der  Aufziihlung  der  Wirkungsgesetze  ohne 
Riicksicht  auf  jede  Erfahrung  beginnen,  so  liegt  es  ganz  in  unserer 
Hand  gleich  anfangs  willkilrlich  festzustellen,  von  welchen  Umstanden 
die  Bewegung  eines  Korpers  abhangt  und  welche  darauf  ohne  Einfluss 
sind.  Bei  der  inductiven  Methode  hingegen  miissen  wir  den  Begriff  der 
unmittelbaren  Umgebung  eines  Korpers,  deren  Zustand  auf  seine  Beweg- 
ung von  Einfluss  ist,  nach  der  Erfahrung  bestimmen.  Nach  der  Nahe- 
wirkungstheorie  sind  es  nur  die  unmittelbar  anliegenden  Volumelemente, 
welche  die  Bewegung  irgend  eines  Volumelementes  bestimmen.  Nach 
dieser  Theorie  wirkt  die  Erde  nicht  direct  anziehend  auf  den  schweren 
Korper  sondern  sie  wirkt  nur  auf  die  Volumelemente  eines  Mediums, 
durch  welche  sich  die  Wirkung  bis  zum  schweren  Korper  fortpflanzt. 
Aber  wenn  wir  den  Principien  unserer  jetzigen  Darstellungsweise  treu 
bleiben  wollen,  so  diirfen  wir  nicht  die  Nahewirkungstheorie  zur  Basis  des 
gesammten  Gebaudes  der  Mechanik  machen,  wir  diirfen  vielmehr  hiezu 
nur  Gesetze  verwenden,  welche  nichts  Willkiirliches  enthalten,  sondern  uns 
durch  die  Erfahrung  eindeutig  und  notwendig  aufgedriingt  werden.  Die 
Nahewirkungstheorie    aber,    so   wahrscheinlich    sie    vielleicht    manchem 


Zweite  Vorlesung.  283 

a  priori  erscheint,  gelit  doch  vollstandig  iiber  das  rein  Thatsachliche  liinaus 
und  kann  heutzutage  noch  keineswegs  ins  Detail  ausgearbeitet  werden. 
Wir  wlirden  da  in  denselben  Feliler  verfallen,  den  wir  der  Hertz'schen 
Darstellungsweise  vorgeworfen  haben.  Wir  miissten  entweder  ganz  will- 
kiirliche  spezielle  Hypotbesen  fiir  die  Art  und  Weise  der  Nabewirkung 
erfinden  oder  uns  mit  allgemeinen  unbestimmten  Vorstellungen  iiber  die- 
selbe  begniigen. 

Wir  miissen  daber  die  ganze  Erde  zur  Umgebung  des  schweren  Kor- 
pers  recbnen  aber  Mond  und  Sterne  dabei  ausser  Acbt  lassen,  da  letztere 
keinen  bemerkbaren  Einfluss  ausiiben.  Es  ist  also  wieder  eine  reine 
Annabme,  welcbe  wir  erst  nachtraglicb  durcb  die  Erfahrung  recbtfertigen 
miissen,  dass  wir  die  unmittelbare  Umgebung  immer  so  abzugrenzen  ver- 
mogen,  dass  wir  alles  Wesentlicbe  einscbliessen  und  dass  wir  so  factiscb 
zu  einer  Aufstellung  von  Bewegungsgesetzen  gelangen  konnen. 

Wie  werden  wir  uns  nun  bei  unserer  jetziger  Darstellungsweise  dem 
absoluten  Raume  und  der  absoluten  Zeit  gegeniiber  verhalten?  An 
einem  Tbeile  des  absoluten  Raumes  konnen  wir  keine  Zirkelspitze  ein- 
setzen  sondern  nur  an  materiellen  Korpern.  Wir  konnen  daher  nur 
die  Bewegung  von  materiellen  Korpern  relativ  gegen  einander  bestimmen. 
Wir  diirfen  jetzt  nicht  wie  bei  der  deductiven  Methode  das  Gedanken- 
bild  eines  fingirten  Coordinatensystems  unter  die  von  uns  gegenwiirtig 
allein  betracbteten  realen  Korper  mengen.  Dem  Geiste  unserer  Metbode 
entsprecbend  miissen  wir  vielmebr  unsere  Betrachtungen  moglicbst  dem 
historischen  Entwickelungsgange  der  Mecbanik  anschliessen.  Galilei 
hat  die  einfacben  Bewegungsgesetze  gefunden,  indem  er  die  Bewegung 
relativ  gegen  die  Erde  studirte.  Seinem  Beispiele  folgend  werden  wir 
daher  ausser  dem  Korper  JT,  dessen  Bewegung  wir  beschreiben  wollen, 
noch  ein  System  von  anderen  Korpern  in  die  Betrachtungen  mit  einbe- 
ziehen,  welche  die  Bedingung  erfiillen,  dass  alle  ibre  Punkte  ihre  Ent- 
fernungen  von  einander  nicht  andern,  dass  sie  also  alle  relativ  ruhen. 
Dieses  System  nennen  wir  das  Bezugssystem.  Wenn  wir  daher  die 
Bewegung  eines  festen  Korpers  gegen  ein  Bezugssystem  studiren  und 
wenn  A^  B,  C  .  .  .  markirte  Punkte  des  ersteren,  ^,  F,  Cr  .  .  .  solche  des 
letztern  sind,  so  andern  sich  weder  die  Entf ernungen  AB,  AO  .  .  .  noch 
UF,  ECr  .  .  .  und  unsere  Aufgabe  besteht  bloss  darin,  die  Gesetze 
der  Veriinderungen,  der  Entfernungen  AE,  AF,  BF  .  .  .  aufzustellen. 
Natiirlich  sind  hiebei  auch  wieder  vielerlei  Idealisirungen  notwendig. 
Wir   werden    kein   System   von    Korpern    als    Bezugssystem    auffinden 


284  Ludivig  Boltzmann: 

konnen,  welche  so  bescliaffen  sind,  dass  sie  zu  alien  Zeiten  relativ  gegen- 
einander  ihre  Lage  absolut  beibehalten.  Es  geiiligt,  wenn  diese  Beding- 
ung  angeniihert  durch  geniigend  lange  Zeit  erfiillt  ist. 

Ferner  konnen  wir  nicht  wissen,  ob  wir  dieselben  Gesetze  erhalten, 
wenn  wir  das  eine  oder  andere  Bezugssystem  wiihlen.  Wir  werden 
daher  jedenfalls  ein  solches  Bezugssystem  zu  wiihlen  haben,  dass  wir  ein- 
fache  Gesetze  fiir  die  Bewegung  erhalten.  Es  zeigt  sich  in  der  That, 
dass  die  Gesetze,  welche  wir  bei  zu  Grundelegung  des  Fixsternhimmels 
als  Bezugssystem  erhalten  nicht  ohne  kleine  Correctionen  auf  die  Beweg- 
ung relativ  gegen  die  Erde  angewandt  werden  konnen  und  es  muss  als 
ein  fiir  die  Entwickelung  der  Mechanik  ausserordentlich  glinstiger  Zufall 
bezeichnet  werden,  dass  der  Einfluss  der  Erddrehung  auf  die  verschiedenen 
Bewegungen,  welche  wir  auf  ihrer  Oberflache  beobachten  ein  so  ausser- 
ordentlich geringer  ist.  Sonst  ware  es  weit  schwieriger  gewesen  die 
Grundgesetze  der  Mechanik  herzuleiten.  Diesem  Umstande  ist  es  zu  ver- 
danken,  dass  wir  fiir  die  Bewegungen  auf  der  Erde  den  Erdkorper  als 
Bezugssystem  wiihlen  konnen.  Wir  erhalten  hiedurch  einfache  Gesetze, 
denen  die  wirklichen  Bewegungen  freilich  nicht  mit  absoluter  Genauig- 
keit  folgen,  aber  die  Abweichungen  sind  so  gering,  dass  sie  sich  fast  der 
Beobachtung  entziehen.  Dies  konnten  wir  freilich  nicht  a  priori  wissen  ; 
aber  es  ist  kein  logischer  Fehler,  wenn  wir  zunachst  die  Gesetze  der 
Relativbewegung  gegen  die  Erde  studiren.  Finden  wir  einfache  Gesetze, 
so  ist  es  wieder  kein  logischer  Fehler,  deren  Anwendung  auf  die  Beweg- 
ung der  Planeten  relativ  gegen  das  Fixsternsystem  zu  versuchen.  Bei 
dieser  Erweiterung  zeigt  sich  dann  erst  einestheils,  dass  sie  auch  fiir  den 
ersten  Fall  angeniihert  richtig  sein  miissen,  anderseits  aber,  dass  derselbe 
doch  kleiner  Correctionen  bedarf.  Diese  Correctionen  sind  so  klein 
dass  sie  uns  bei  Auffindung  der  Gesetze  aus  den  irdischen  Bewegungen 
nicht  storten,  dass  sie  aber  jetzt  nachdem  wir  ihre  Grossenordnung  kennen 
gelernt  haben  doch  mit  feinen  Hilfsmitteln  beobachtet  werden  konnen. 
Dass  die  wirklichen  Bewegungen  dann  gerade  die  durch  diese  Correctionen 
bedingten  Eigenthiimlichkeiten  zeigen,  reehtfertigt  nachher  in  gliinzender 
Weise  unsere  Methode.  Hiemit  ist  wieder  die  piidagogische  Schwierig- 
keit  beseitigt,  welche  durch  die  Relativitiit  aller  Bewegungen  bedingt 
wird.  Die  Frage,  auf  welches  Bezugssystem  wir  die  Fixsternbewegungen 
zu  beziehen  haben,  ist  hiemit  freilich  nicht  gelost,  aber  es  liegt  in  keiner 
Weise  eine  Notwendigkeit  vor,  diese  Frage  vor  Aufstellung  der  siimmt- 
lichen  Gesetze  der  Mechanik  zu  behandeln. 


Zweite  Vorlesimg.  285 

Wir  haben  bisher  iiber  die  Gestalt  und  Anordnung  der  Korper  des 
zu  Grunde  gelegten  Bezugssystems  keine  besondere  Annahme  gemacht. 
Es  hat  nun  keine  Schwierigkeit  mit  denselben  drei  fixe  auf  einander 
rechtwinklige  Gerade  vorbunden  zu  denken,  welche  man  als  Coordinaten- 
axen  wiihlen  kann.  Die  Lage  jedes  an  dem  betreffenden  Korper  mar- 
kirten  Punktes  ist  dann  zu  jeder  Zeit  durch  dessen  rechtwinklige 
Coordinaten  beziiglich  dieses  Coordinatensystems  bestimmt.  Wenn 
sich  diese  mit  der  Zeit  nicht  andern,  so  befindet  sich  der  Korper 
in  relativer  Ruhe  gegen  das  Bezugssystem.  Wenn  sie  sich  andern, 
so  ist  er  in  Bewegung  Um  den  letztern  Fall  beschreiben  zu  konnen, 
ist  noch  die  genaue  Fixirung  des  Zeitmasses  erforderlich.  Gerade 
so  wie  wir  schon  mit  Hilfe  des  Augenmasses  oder  des  Tastgefiihles 
grossere  raumliche  Ausdehnungen  von  kleineren  unterscheiden,  einen 
genauen  zahlenmassigen  Ausdruck  der  Raumgrosse  aber  nur  durch  Ver- 
gleich  mit  einem  rationell  construirten  Massstabe  gewinnen  konnen,  so 
konnen  wir  auch  schon  durch  das  Gefiihl  (den  Zeitsinn)  langere  Zeit- 
raume  von  kiirzern  unterscheiden,  miissen  uns  aber  ein  genaues  quantita- 
tives  Zeitmass  durch  die  Hilfsmittel  verschaffen,  welche  schon  in  der 
ersten  Vorlesung  angedeutet  wiirden.  Wir  miissen  uns  da  vor  allem 
eine  Reihe  von  Vorgangen  verschaifen,  bei  denen  wir  vollkommen  oder 
besser  gesagt,  thunlichste  Garantie  haben,  dass  sie  sich  in  gleichen  Zeiten 
abspielen.  Wir  konnen  etwa  ganz  gleiche  Korper  unter  ganz  gleichen 
Umstiinden  fallen  lassen  oder  ganz  gleiche  Pendel  um  gleiche  Strecken 
aus  der  Ruhelage  entfernen.  Wenn  das  erste  die  Ruhelage  erreicht, 
lassen  wir  das  zweite  seine  Bewegung  beginnen  etc.  Ob  wir  gegenseitige 
Storungen  wirklich  geniigend  vermieden  haben,  kann  natiirlich  nur  der 
Vergleich  mit  verschiedenen  analogen  Versuchen  zeigen.  Wir  sehn 
natiirlich  bald,  dass  auch  ein  Pendel  die  verschiedenen  sich  folgenden 
Schwingungen  nahe  unter  den  gleichen  Umstanden  vollzieht  und  konnen 
diese  zur  Zeitmessung  benutzen.  Freilich  ist  der  absolute  Isochronismus 
der  Schwingungen  wieder  ein  Ideal,  Temperatur,  Barometerstand,  Sonne 
und  Mond  haben  darauf  Einfluss,  aber  wie  alle  diese  storenden  Umstande 
bei  gut  gearbeiteten  Chronometern  moglichst  vermieden  werden,  wie 
durch  eine  treibende  Kraft  die  Schwingungen  sehr  lange  erhalten  werden, 
dass  man,  wenn  ein  bestimmtes  Chronometer  endlich  unbrauchbar  wird, 
dafiir  ein  anderes  moglichst  gleichbeschaffenes  substituiren  kann,  das 
alles  ist  nicht  mehr  Sache  unserer  gegenwartigen  allgemeinen  Betrach- 
tungen. 


286  Ludwig  Boltzmann: 

Wir  wahlen  einen  bestimmten  Zeitmoment  z.  B.  den,  der  einem 
bestimmten  willkiirlich  gewiihlten  Durchgang  durch  die  Ruhelage  ent- 
spricht,  als  Zeitmoment  Null,  den  des  ntichsten  Durchgangs  durch  die 
Rulielage  als  Zeit  1,  die  welter  folgenden  als  die  Zeiten  2,  3  u.s.w.  Die 
Unterabtheilungen  konnen  wir  durch.  schneller  schwingende  Stimmgabeln 
oder  durch  Bewegungen  bestimmen,  die  sich  fiir  grossere  Intervalle  unter 
alien  Umstanden  als  geniigend  gleichformig  erwiesen  und  von  denen  wir 
Ursache  haben  dies  auch  fiir  kleinere  Intervalle  zu  vermuten.  So  gewin- 
nen  wir  die  Zeiten  ^,  \  u.s.w  und  es  lasst  sich  keine  Grenze  der 
Unterabtheilung  feststellen.  Die  negativen  Zahlen  bezeichnen  die 
Schwingungen  vor  derjenigen  der  wir  die  Zeit  Null  zugeordnet  haben. 
In  dieser  Weise  kdnnen  wir  alle  Zeiten  durch  positive,  negative,  ganze, 
gebrochene,  irrationale  Zahlen  darstellen,  wie  wir  die  Langen  durch  die 
Zahl  darstellen,  welche  angibt,  wie  oftmals  sie  die  Liingeneinheit  enthal- 
ten.  Die  Differenz  der  Zahlen,  welche  zwei  gegebene  Zeiten  darstellen 
heisst  das  dazwischen  liegende  Zeitintervall  oder  die  Zeitdifferenz  auch 
die  inzwischen  vorflossene  Zeit.  Unsere  gewohnliche  Zeiteinheit  leiten 
wir  von  der  Umdrehungszeit  der  Erde  ab,  deren  Gleichformigkeit  aber 
bei  Ableitung  der  Principien  der  Mechanik  wol  besser  durch  einfachere 
Vorgange  controlirt  wird,  da  es  ohne  Kenntnis  der  mechanischen  Gesetze 
nicht  so  ohne  welters  evident  ist,  dass  die  Umdrehungsgeschwindigkeit 
an  alien  Stellen  der  Erdbahn  dieselbe  bleibt. 

Wir  kehren  nun  zuriick  zu  unserem  Korper  K^  den  wir  auf  ein  mit 
dem  gewahlten  Bezugssysteme  fest  verbundenes  Coordinatensysten  Ox^ 
Oy^  Oz  beziehen.  Ein  auf  demselben  hervorgehobener  Punkt  befinde 
sich  zu  einer  bestimmten  Zeit  t  m.  A  und  habe  die  rechtwinkeligen  Coor- 
dinaten  x,  ?/,  z.  Wir  verbinden  ihn  durch  die  Gerade  OA  mit  dem  Coor- 
dinatenursprunge :  Diese  Gerade  heisst  der  Lagenvector  des  Punktes  A^ 
ihre  Projectionen  auf  die  drei  Coordinatenaxen  sind  die  drei  Coordinaten 
a;,  ^,  z.  Wenn  nun  der  Korper  eine  gewisse  gegebene  Bewegung  macht, 
so  miissen  wir  zunachst  jeden  Zeitmoment  der  Bewegung  etwa  durch 
Vergleichung  der  gleichzeitigen  Bewegung  unseres  Chronoskops  durch 
eine  Zahl  darstellen.  Es  wird  zu  jeder  Zeit  eine  bestimmte  Lage  des 
Korpers  gehoren,  daher  auch  des  Punktes  A  desselben,  daher  auch  be- 
stimmte Werte  der  Coordinaten  t/,  a;,  2,  welche  wir  uns  ebenfalls  durch 
reine  Zahlen  (ganze  oder  gebrochene  Vielfache  der  Langeneinheit)  dar- 
gestellt  denken.  Zu  jedem  Zahlenwerte  der  Zeit  t  gehort  also  ein  ein- 
deutig  bestimmter   Zahlenwert  der   Coordinate  x,  x  ist  eine  eindeutige 


Zweite  Vorlesung.  287 

Funktion  von  t,  ebenso  y  unci  z.  Wir  schreiben  dies  so  x=^(t), 
y  =  x(0^  ^  =  "^(0  ^^nd  nennen  t  das  Argument  oder  die  independente 
Variabele,  x,  y,  z  aber  die  dependenten  Variabeln.  Wir  konnen  es  zu- 
nachst  als  hinlanglich  sicher  gestellte  Erfahrungsthatsache  betrachten, 
dass  ein  Korper  nie  aus  einer  Lage  plotzlich  verschwindet  und  im 
nachsten  Zeitmomente  in  einer  andern  um  Endliches  davon  Ver- 
schiedenen  wieder  zum  Vorschein  kommt  und  dass  dies  auch  von  jedem 
Theile  eines  Korpers  gilt,  dass  also  ^,  x->  i^  continuirliche  Functionen 
der  Zeit  sind,  d.  h.  ihre  Zuwachse  verschwinden  um  so  mehr  je  kleiner 
der  entsprechende  Zuwachs  der  Zeit  ist.  Die  von  den  verschiedenen 
Lagen  des  Punktes  A  zu  den  verschiedenen  Zeiten  gebildete  Curve  nen- 
nen wir  die  Bahn  dieses  Punktes,  denjenigen  Theil  derselben,  welcber 
alien  Lagen,  die  wahrend  einer  gegebenen  Zeit  durchlaufen  werden  ent- 
spricht  den  wahrend  dieser  Zeit  zuriick  gelegten  Weg. 

Nicht  ganz  so  sicher  als  die  Continuitat  der  Functionen  <^,  ^i  "^  ist 
es,  ob  sie  auch  differenzirbar  sind.  Man  driickte  sich  in  der  alten 
Mechanik  folgendermassen  aus.  Es  lege  ein  Punkt  eines  Korpers,  wahr- 
end einer  sehr  kleinen  Zeit  Bt  einen  sehr  kleinen  Weg  Ss  zuriick.  Es  sei 
nun  a  priori  evident,  dass  sich  wahrend  dieser  kleinen  Zeit,  die  Umstande, 
unter  denen  sich  der  Korper  befindet  nur  sehr  wenig  geandert  haben  kon- 
nen, dass  es  daher,  wahrend  der  nachst  folgenden  Zeit  Bt  wieder  einen 
sehr  nahe  gleichen  und  gleich  gerichteten  Weg  Bs  zurlicklegen  muss,  so 
dass  also  fiir  kleine  Zeiten  sowohl  der  Weg  als  auch  die  Coordinatenzu- 
wachse  der  verstrichenen  Zeit  proportional  sein  miissen.  Man  glaubte 
damals  iiberhaupt,  dass  jede  iiberall  endliche  continuirliche  Function  einen 
Differenzialquotienten  haben  muss.  Weierstrass  hat  bekanntlich  gezeigt, 
dass  dies  ein  Irrthum  ist.  Bezeichnen  wir  z.  B.  mit  y  die  Weierstrass- 
ische  Reihe  so  nahert  sich  der  Zuwachs  des  y,  der  irgend  einem  Zuwachse 
des  X  entspricht  an  alien  Stellen  immer  mehr  der  Nulle,  wenn  sich  der 
betreffende  Zuwachs  das  x  der  Nulle  nahert  und  trotzdem  nahert  sich 
der  Quotient  beider  Grossen  niemals  einer  bestimmbaren  Grenze.  Bei 
der  deductiven  Darstellung  ergibt  sich  hieraus  wieder  nicht  die  mindeste 
Schwierigkeit.  Wir  konnen  ja  dann  unser  Bild  formen,  wie  wir  woUen 
und  einfach  die  Differenzirbarkeit  von  vornherein  in  dasselbe  aufneh- 
men,  es  damit  rechtfertigend,  dass  das  Bild  hinterher  mit  der  Erfahrung 
stimmt.  Aber  jetzt  ist  es  unsere  Absicht  von  der  Erfahrung  auszugehn. 
Nun  lehrt  uns  zwar  diese,  dass  sehr  haufig,  wahrend  kleiner  noch  beob- 
achtbarer  Zeiten  der  Weg  eines  Punktes  eines  Korpers  um  so  genauer 


288  Luclwig  Boltzmcmn: 

der  verflossenen  Zeit  proportional  ist,  je  kiirzer  diese  ist,  woraus  wir  wohl 
auf  die  Differenzirbarkeit  der  Functionen  0,  %,  i/r  schliessen  konnen. 
Allein  wir  kennen  auch  Beispiele  sehr  rascher  Oscillationen  uiid  konnen 
nicht  exact  beweisen,  ob  nicht  in  gewissen  Fallen  Bewegungen  vorhanden 
sind,  wie  z.  B.  die  Warmebewegungen  der  Molekiile,  welche  durch  eine 
der  Weierstrass'schen  Function  ahnliclie  besser  als  durch  eine  Differen- 
zirbare  dargestellt  werden.  Doch  sind  dies  allerdings  Dinge  von  gering- 
erer  Wichtigkeit  und  wir  wollen  daher  die  Differenzirbarkeit  der  Coor- 
dinaten  nach  der  Zeit  unsern  weitern  Uberlegungen  zu  Grunde  legen. 
Unter  dieser  Voraussetzung  existiren  die  Ableitungen  der  Functionen 
<^,  %,  -^  nach  der  Zeit.  Wir  nennen  sie  die  Componenten  der  Geschwin- 
digkeit  des  Punktes  A  des  Korpers.  Die  Geschwindigkeit  selbst  konnen 
wir  in  folgender  Weise  construiren :  Es  befinde  sich  der  markirte  Punkt 
des  Korpers  zur  Zeit  t  \n  A  zur  Zeit  t -{- Win  B,  so  dass  also  OA,  und  OB 
die  dazu  gehorigen  Lagenvectoren  sind.  Die  Gerade  AB  ist  dann  das, 
was  man  die  Differenz  der  beiden  Vectoren  nennt.  Wir  construiren 
nun  einen  Vector,  welcher  die  Richtung  AB  hat  und  dessen  Lange  der 
Quotient  AB  dividirt  durch  8t  ist.  Ferner  suchen  wir  die  Grenze,  wel- 
cher sich  dieser  Vector  in  Grosse  und  Richtung  nahert,  wenn  Bt  immer 
mehr  abnimmt.  Die  so  bestimmte  Lange  ist  die  Geschwindigkeit,  die 
Richtung  aber,  der  sich  der  Vector  nahert,  die  Geschwindigkeitsrichtung. 
Wir  wollen  hier  noch  eine  Bemerkung  anfiigen.  Damit  wir  den  Weg 
durch  die  verfiossene  Zeit  dividiren  konnen,  miissen  beide  durch  reine 
Zahlen  ausgedriickt  sein  und  wir  haben  gesehen  wie  dies  geschieht. 
Wahlen  wir  die  Langeneinheit  a  mal  so  gross,  so  wird  die  Zahl,  welche 
nun  eine  gewisse  Lange  ausdriickt  a  mal  kleiner.  Es  ist  moglich,  dass 
auch  andere  Grossen  dieselbe  Eigenschaft  haben,  dass  sie  durch  a  mal 
kleinere  Zahlen  ausgedriickt  erscheinen,  sobald  wir  die  Langeneinheit 
a  mal  vergrossern.  Von  alien  so  beschaffenen  Grossen  sagen  wir  dann, 
dass  sie  die  Dimension  einer  Lange  haben.  Jede  Lange,  (der  Weg,  die 
Coordinaten  etc.)  hat  daher  selbstverstandlich  die  Dimension  einer  Lange. 
Die  Zahl,  welche  uns  die  Zeit  t  ausdriickt,  ist  natlirlich  unabhangig  von 
der  gewahlten  Langeneinheit,  wird  aber  a  mal  kleiner,  wenn  wir  die 
Zeiteinheit  a  mal  grosser  wahlen  und  wir  sagen  von  jeder  Grosse,  welche 
durch  eine  Zahl  von  dieser  Eigenschaft  ausgedriickt  wird,  sie  habe  die 
Dimension  einer  Zeit.  Die  Geschwindigkeit  wird  durch  den  Quotienten 
zweier  Zahlen  gemessen,  wovon  der  Zahler  die  Dimension  einer  Lange, 
der  Nenner  die  einer  Zeit  hat.     Sie  ist  also  sowohl  von  der  Wahl  der 


Zweite  Vorlesung.  289 

Langen  als  auch  von  der  Zeiteinheit  abhangig,  und  wird  a  mal  kleiner, 
wenn  die  erstere  a  mal  grosser,  dagegen  a  mal  grosser,  wenn  die  letztere 
a  mal  grosser  gewahlt  wird.     Wir  sagen  daher  ihre  Dimensionen  sind : 
Lange  dividirt  durch  Zeit,  was  aber  hiemit  jeder  geheimnisvollen  oder 
metaphysischen  Bedeutung  eutkleidet  ist.     Man  redet  vielfacli  statt  von 
dem  Quotienten  der  Zahl  welclie  die  Zeit  ausdriickt  in  die,  welclie  die 
Lange  ausdriickt,  einfach  von  dem  Quotienten  einer  Zeit,  in  eine  Lange. 
Man  hat  da  den  Begriff  der  Division  erweitert  und  muss  den  Quotienten 
einer  Zeit  in  eine  Lange  ganz  neu  definiren,  geradeso  wie  man  den  Begriff 
einer  negativen  oder  gebrochenen  Potenz  neu  definirt  und  darunter  einen 
Bruch  respektive  eine  Wurzel  versteht.     Der  Vortheil  dieser  neuen  Defi- 
nition besteht  darin,  dass  man  vielfacli  Rechnungsregeln,  welclie  fur  die 
friihere  Definition  bewiesen  wurden  auf  die  neue  Definition  iibertragen 
kann.     Man  darf  aber  nicht  a  priori  schliessen,  dass  dies  von  alien  Rech- 
nungsregeln gilt ;  es  muss  vielmehr  die  Ubertragbarkeit  von  jeder  Rech- 
nungsregel  besonders  bewiesen  werden.     Ebenso  ist  es  eine  vollstiindig 
neue  Definition,  wenn  wir  unter  der  zweiten  oder  dritten  Potenz  eines  Cen- 
timeters die  geometrische  Figur  eines  Quadrats  oder  Wiirfels  von  1  cm. 
Seitenlange  verstehen  und  es  muss  gerechtfertigt  werden,  in  wie  weit 
diese  neue  Definition  zweckmassig  ist.     Die  Fixirung  des  Begriffs  der 
Beschleunigung   und   ihrer   Componenten   nach   den    drei   Coordinaten- 
richtungen  hat  nun  nicht  mehr  die  mindeste  Schwierigkeit.     Sei  A  Q  der 
Vector,  welcher  in  Grosse  und  Richtung  die  Geschwindigkeit  zur  Zeit 
t,  OB  der,  welcher  sie  zur  Zeit  t-^U  darstellt.     Wir  ziehen  die  Gerade 
(72),  also  die  Differenz  der  beiden  Vectoren.      Dieselbe  wird  sehr  klein 
sein,  wenn  ht  sehr  klein  ist.     Wir  erhalten  aber  eine  endlich  bleibende 
Gerade,  wenn  wir  sie  im  Verhaltnis  der  Zeiteinheit  zur  Zeit  U  vergross- 
ern,  wobei  ihre  Richtung  unverandert  bleiben  soil.     Die  Grenze,  welcher 
sich  der  so  vergrosserte  Vector  CD  mit  abnehmendem  ht  nahert,  heisst 
der  Beschleunigungsvector,  seine  Lange  stellt  die  Grosse,  seine  Richtung 
die  Richtung  der  Beschleunigung  dar.     Seine  Componenten  in  den  drei 
Coordinatenrichtungen  heissen   die    Componenten    der   Beschleunigung. 
Man  iiberzeugt  sich  in  bekannter  Weise,  dass  es  die  zweiten  Ableitungen 
der   friiher  mit  x^  </>'  "^  bezeichneten  Functionen   sind.      Wir   mlissen 
daher   die   Voraussetzung   machen,  dass   diese   Functionen  auch  zweite 
Ableitungen   haben.     Man   iiberzeugt  sich  auch  leicht,  dass   die    Zahl, 
welche  die  Grosse  der  Beschleunigung  ausdriickt  wieder  sowohl  von  den 
gewahlten  Langen  als  von  der  gewahlten  Zeiteinheit  abhangt  und  a  mal 


290  Ludwig  Boltzniann: 

kleiner  wird,  wenn  erstere  a  mal  so  gross,  dagegen  a?-  nial  grosser,  wenn 
die  Zeiteinheit  a  mal  so  gross  gewiihlt  wird.  Wir  werden  daher  sagen, 
die  Beschlemiigung  hat  die  Dimensionen :  Liinge  dividirt  durch  das 
Quadrat  der  Zeit.  Wir  konnen  wieder  die  Beschleunigung  als  solche 
definiren  als  den  Quotienten  einer  Zeit  in  eine  Geschwindigkeit  oder  des 
Quadrats  einer  Zeit  in  eine  Lange ;  diirfen  aber  die  letzteren  Defini- 
tionen  nur  mit  einer  gemssen  Vorsicht  anwenden,  da  sie  Erweiterungen 
des  Begriffs  der  allgebraischen  Division  darstellen,  fiir  welche  die  An- 
wendbarkeit  der  verscliiedenen  in  der  Algebra  bewiesenen  Rechnungs- 
regeln  erst  neu  erprobt  werden  muss. 

Nachdem  wir  diese  Begriffe  moglichst  an  die  Erfabrung  ankniipfend 
entwickelt  haben,  miissen  wir  zur  Aufstellung  der  Gesetze  iibergehn, 
nach  welcben  die  Bewegung  der  Korper  gescbielit.  Wir  werden  da 
natiirlich  wieder  nicht  mit  Aufstellung  der  Gesetze  fiir  die  Bewegung 
eines  materiellen  Punktes  beginnen,  da  dieser  eine  reine  Abstraction  ist. 
Wir  werden  uns  natiirlich  auch  nicht  der  Illusion  hingeben,  dass  wir  ohne 
alle  Abstractionen  auskommen.  Wir  konnen  nach  meiner  Ansicht  nicht 
einen  einzigen  Satz  aussagen,  welcher  wirklich  nur  eine  reine  Erfahrungs- 
thatsache  ware.  Die  einfachsten  Worte  wie  gelb,  siiss,  sauer  etc.,  welche 
blosse  Empfindungen  anzugeben  scheinen,  driicken  schon  Begriffe  aus, 
die  bereits  aus  vielen  Erfahrungsthatsachen  durch  Abstraction  gewonnen 
worden  sind.  Wenn  Gothe  sagt,  die  Erfahrung  ist  nur  zur  Halfte 
Erfahrung  so  will  er  mit  diesem  scheinbar  paradoxen  Satze  sicher  aus- 
drlicken,  das  wir  bei  jeder  begrifflichen  Auffassung  der  Erfahrung  oder 
Darstellung  derselben  durch  Worte  schon  liber  die  Erfahrung  hinaus- 
gehen  miissen.  Die  oft  aufgestellte  Forderung,  dass  die  Naturwissen- 
schaft  nie  iiber  die  Erfahrung  hinausgehen  diirfe,  sollte  daher  nach 
meiner  Ansicht  dahin  ausgesprochen  werden,  dass  man  nie  zu  weit  iiber 
die  Erfahrung  hinaus  gehen  diirfe  und  nur  solche  Abstractionen  ein- 
fiihren  soUe,  die  sich  bald  wieder  an  der  Erfahrung  priifen  lassen.  Wir 
werden  auch  nicht  das  Tragheitsgesetz  an  die  Spitze  stellen.  Dieses  mag 
theoretisch  das  einfachste  Gesetz  der  Mechanik  sein,  physikalisch  ist  es 
keineswegs  das  einfachste,  da  es  eine  ganze  Reihe  von  Abstractionen 
zur  Voraussetzung  hat,  worauf  ich  schon  friiher  hingewiesen  habe.  Als 
die  beiden  physikalisch  einfachsten  Falle  erscheinen  uns  vielmehr  erstens 
der  der  relativen  Ruhe  zweitens,  der  freie  Fall  eines  schweren  Korpers. 
Wie  wir  sahen,  konnen  wir  einen  Korper  niemals  ganz  den  aussern  Ein- 
fliissen  entziehen.     Wenn  nun  solche  Einfliisse  vorhanden  sind,  von  denen 


Ztveite  Vorlesung.  291 

jeder  fiir  sich  allein  eine  Bewegung  erzeugen  wiirde,  wenn  aber  unter  dem 
vereinten  Einflusse  aller  relative  Ruhe  gegen  das  Bezugssystem  Platz 
greift,  so  sagen  wir  alle  Ursachen  der  Relativbewegung  compensiren  sich. 
Ich  konnte  micli  auch  des  gebrauchlichsten  Ausdruckes  bedienen,  die 
Krafte  halten  sich  das  Gleichgewicht,  allein  ich  will  absichtlich  die  gewohn- 
ten  Ausdriicke  vermeiden,  well  wir  mit  denselbeii  unwillkiirlich  eine  Menge 
von  Vorstellungen  verbinden,  die  sich  dann,  ohne  dass  wir  es  wollen, 
unkontrolirt  in  unsere  Schlussweise  einschmuggeln  und  so  den  Schein 
erwecken,  als  hatten  wir  etwas  bewdesen,  was  wir  nur  gemass  unserer 
alten  Denkgewohnheit  und  Ideenassociation  ohne  Begriindung  beigefiigt 
haben.  Ich  will  ausserdem  das  Wort  Kraft  vermeiden,  ehe  ich  gleich- 
zeitig  auch  von  der  Masse  sprechen  kann.  Endlich  betrachten  wir  liier 
nur  die  relative  Bewegung.  Es  kann  aber  ein  Korper  relativ  gegen 
seine  Umgebung  ruhen,  ohne  dass  sich  die  auf  ihn  wirkenden  Krafte  das 
Gleichgewicht  zu  halten  brauchen  wie  ein  Korper,  der  relativ  gegen  einen 
mit  Beschleunigung  sich  bewegenden  Lift  ruht. 

Wir  betrachten  nun  einen  bestimmten  Fall,  wo  die  Ursachen  der 
relativen  Bewegung  compensirt  sind.  Ein  schwerer  Korper  sei  an  einen 
diinnen  Faden  aufgehangt.  Wir  konnten  da  meinen,  dass  gar  keine 
Bewegungsursachen  vorhanden  sind.  Doch  finden  wir,  dass  sofort 
Bewesfung-  eintritt,  wenn  wir  den  Faden  entfernen.  Es  mlissen  also 
mindestens  zwei  Bewegungsursachen  vorhanden  gewesen  sein,  welche 
sich  gegenseitig  compensirten. 

Wenn  wir  die  nach  Entfernung  des  Fadens  eintretende  Bewegung 
analysiren,  so  finden  wir,  dass  sie,  wenn  gewisse  allgemeine  Bedingungen 
erfiillt  sind,  sehr  angeniihert  immer  in  derselben  Weise  vor  sich  geht. 
Diese  allgemeinen  Bedingungen  sind  folgende.  Die  Oberflache  des 
Korpers  darf  nicht  zu  gross  gegen  dessen  Gewicht  sein,  es  darf  keine 
heftige  Luftbewegung  um  den  Korper  herum  stattfinden,  der  Faden  muss 
ohne  Erschlitterung  durchgeschnitten  oder  ruhig  durch  Verbrennung 
oder  sonst  wie  vernichtet  worden  sein.  Dieselbe  Bewegung  tritt  auch 
ein,  wenn  wir  den  Korper  anfangs  mit  der  Hand  oder  einer  Zange  oder 
einer  sonstigen  Vorrichtung  halten  und  plotzlich  ohne  Erschiitterung 
sich  selbst  iiberlassen.  Das  Charakteristische  aller  dieser  Anfangs- 
bedingungen  besteht  darin,  dass  sammtliche  Punkte  des  Korpers  in  den 
ersten  Momenten  der  Bewegung  sehr  kleine  Geschwindigkeiten  haben. 
Wir  konnen  daher  anniihernd  voraussetzen,  dass  sammtliche  Punkte  des 
Korpers  im  ersten  Momente  der  Bewegung  keinerlei  Anfangsgeschwindig- 


292  Ludioifj  Boltzmann: 

keit  batten.  Wenn  diese  Bedingungen  erfiillt  sind,  so  lehrt  die  Erfahr- 
ung,  dass  der  Korper  stets  fast  genau  nach  denselben  Gesetzen  sich 
bewegt,  wo  immer  er  in  der  Niihe  der  Erdoberflache  sicb  selbst  iiberlassen 
worden  sei.  Die  Bewegung  bestimmen  wir  dabei  natiirlich  einstweilen 
relative  gegen  die  Erde.  Wenn  wir  uns  nocb  auf  einen  nicbt  zu  grossen 
Theil  der  Erdoberflache  bescliriinken,  so  ist  auch  die  Ricbtung  der 
Bewegung  iiberall  dieselbe ;  es  ist  die  des  Fadens,  der  friiher  den 
Korper  trug.  Die  Erfahrung  lehrt  nun  fiir  diese  Bewegung  die  folgen- 
den  Gesetze.  Erstens  der  Korper  bewegt  sich  parallel  zu  sich  selbst,  d.  h. 
alle  Punkte  desselben  legen  in  gleichen  Zeiten,  gleiche  und  gleichgerich- 
tete  Wege  zuriick.  Da  also  die  Balin  fiir  jeden  Punkt  dieselbe  ist,  so 
kann  man  sie  als  die  Bahn  des  ganzen  Korpers  bezeichnen.  Zweitens,  alle 
diese  Wege  sind  geradlinig.  Drittens,  die  Geschwindigkeit  wachst  fort- 
wahrend,  die  Beschleunigung  ist  jedoch  iiberall,  zu  alien  Zeiten  und  sogar 
fiir  alle  Korper  dieselbe.  Dass  diese  Gesetze  in  der  Natur  nur  mit 
grosserer  oder  geringerer  Annaherung  realisirt  sind,  wurde  bereits 
besprochen, 

Wir  konnen  nun  dasselbe  Experiment  wiederholen,  nur  dass  wir  dem 
Korper  im  Momente,  wo  wir  ihn  sich  selbst  iiberlassen  einen  Stoss  geben, 
oder  sonst  me  bewirken,  dass  er  schon  anfangs  eine  Geschwindigkeit  hat. 
Da  wir  die  Satze  vom  Schwerpunkt  und  der  Drehung  der  Korper  noch 
nicht  kennen  gelernt  haben,  so  miissen  wir  uns  dabei  auf  die  Falle 
beschranken,  wo  sich  der  Korper  wieder  parallel  zu  sich  selbst  bewegt. 
Es  wird  dies  zwar  nicht  immer  eintreten  und  wir  konnen  die  Bedingungen 
dafiir,  dass  es  eintritt  noch  nicht  angeben,  aber  in  vielen  Fallen  wird 
dies  stattfinden  und  diese  Falle  wollen  wir  vorlaufig  allein  betrachten. 
In  alien  diesen  Fallen  legen  wieder  alle  Punkte  des  Korpers  gleiche 
Bahnen  zuriick,  welche  wir  also  als  die  Bahn  des  Korpers  bezeichnen 
konnen.  Die  ganze  Bewegung  kann  wieder  dahin  beschrieben  werden, 
dass  die  Beschleunigung  immer  vertikal  nach  abwiirts  gerichtet  und 
iiberall  zu  alien  Zeiten  und  fiir  alle  Korper  dieselbe  ist.  Da  wir  nun 
gesehen  haben,  dass  die  Bewegung,  wenn  wir  sie  an  verschiedenen  Stellen 
im  Zimmer  oder  in  dessen  Umgebung  beginnen  lassen,  immer  in  ganz 
gleicher  Weise  vor  sich  geht,  so  miissen  wir  schliessen,  dass  die  Beweg- 
ungsursache,  welche  wir  Kraft  nennen,  daselbst  iiberall  unveranderlich 
dieselbe  ist.  Anderseits  ist  auch  die  Beschleunigung  unveranderlich 
dieselbe,  wir  konnen  daher  schliessen,  dass  wenigstens  in  diesem  speziellen 
Falle  die  Beschleunigung  das   fiir  die  Kraft  Massgebende  ist  und  well 


Dritte  Vorlesung.  293 

erstere  iiberall  vertikal  nach  abwarts  gerichtet  ist,  so  sagen  wir  auf  den 
Korper  wirkt  eine  constante  vertikal  nach  abwarts  gerichtete  Kraft  die 
Schwere. 

Dritte  Vorlesung. 

Um  tiefer  in  die  Gesetze  der  Bewegungen  einzudringen,  miissten  wir 
jetzt  die  nachst  einfachsten  Falle  betrachten.  Ein  naives  Gemiit  konnte 
da  wohl  meinen,  dass  wir  nun  die  Gesetze  nach  denen  ein  Grashalm  wachst, 
untersuchen  soUten.  Leider  aber  wissen  wir  iiber  diese  noch  heute  fast 
gar  nichts.  Besser  ware  es  schon  die  Gesetze  der  Wirkung  gespannter 
Schnlire,  Federn  etc.  zu  betrachten.  Allein  auch  da  treten  die  Beweg- 
ungsgesetze  nicht  in  grosster  Einfachheit  hervor.  Der  historische  Gang 
war  vielmehr  der  folgende.  Nachdem  Galilei  die  Bewegungsgesetze 
soweit  wir  sie  bisher  betrachtet  haben,  gefunden  hatte,  suchte  Newton 
sie  vor  allem  auf  die  Bewegung  der  Gestirne  anzuwenden  und  auch  von 
ihm  gilt,  was  Schiller  von  Wallenstein  sagte:  ^^Fiirwahr  ihn  hat  kein 
Wahn  betrogen  als  er  auf  warts  zu  den  Sternen  sah."  Dem  Laufe  der 
Sterne  hat  er  die  Bewegungsgesetze  abgelauscht,  auf  denen  alle  heute  in 
der  Technik  und  Machinenlehre  benutzten  Formeln  ja  iiberhaupt  unsere 
ganze  moderne  Naturkenntnis  basirt.  Freilich  bringt  der  Ubergang  zur 
Sternenwelt  manche  Unbequemlichkeit  mit  sich.  Erstens  miissen  wir 
um  einfache  Gesetze  zu  erhalten,  unser  altes  Bewegungssystem,  als  welches 
der  Erdkorper  diente,  verlassen  und  ein  relativ  gegen  den  Fixsternhimmel 
sich  nicht  drehendes  Coordinatensystem  wahlen.  Zweitens  ist  auch  die 
Bedingung,  das  die  Planeten  sich  parallel  zu  sich  selbst  bewegen  nicht 
erfiillt.  An  ihre  Stelle  tritt  der  Umstand,  dass  ihre  Entfernungen  vom 
Beobachter  so  gross  sind,  dass  ihre  einzelnen  Theile  iiberhaupt  nur  schwer 
unterschieden  werden  konnen,  so  dass  wir  also  in  der  ersten  Annaherung 
mit  welcher  wir  uns  wieder  begniigen,  iiberhaupt  die  Bahnen  der  ver- 
schiedenen  Punkte  eines  und  desselben  Planeten  gar  nicht  unterscheiden 
konnen.  Wir  konnen  also  wohl  auch  annehmen,  dass  die  Gesetze  dieselben 
waren,  wenn  die  Himmelskorper  sich  parallel  zu  sich  selbst  bewegten. 
Wir  kommen  also  hier  einestheils  dem  Begriffe  des  materiellen  Punktes 
sehr  nahe,  da  die  Ausdehnung  der  bewegten  Korper  so  klein  gegen  die 
Lange  ihrer  Bahn  ist,  dass  letztere  fiir  alle  Punkte  der  Korpers  merklich 
gleich  wird.  Anderseits  aber  sind  wir  von  dieser  Idee  so  weit  entfernt 
als  moglich,  da  wir  es  mit  Korpern  zu  thun  haben,  die  nichts  weniger  als 
materielle  Punkte,  vielmehr  oft  grosser  als  unser  ganzer  Erdkorper  sind. 


294  Ludwig  Boltzmann  : 

Die  Beobachtung  und  Messung  lehrt,  dass  sich  im  Weltraume  haufig 

um  einen  Centralkorper  ein  System  von  Himmelskorpern  bewegt,  welclie 

wir  die  Trabanten  nennen.      Wir  erhalten  die  einfachsten  Gesetze,  wenn 

wir  die  Bewegung  der  Trabanten  auf  ein  Coordinatensystem  beziehen, 

dessen  Anfangspunkt  im  Mittelpunkte  des  betreffenden  Centralkorpers 

liesft  und  dessen  Axen  dreien  fest  mit  dem  Fixsternhiramel  verbundenen 

Geraden  stets  parallel  bleiben.     Fiir  die  Bewegung  der  Trabanten  gelten 

erfahrungsgemass  die  drei  Keppler'schen  Gesetze.     Da  beim  freien  Falle 

die  Beschleunigung  eine  so  wichtige  Rolle  spielte,  so  wollen  wir  auch 

in  diesem  Falle  die  Beschleunigung  berechnen,  welche  irgend  ein  Tra- 

bant  in  seiner  Bewegung  erfahrt.     Diese  Rechung  ist  sebr  bekannt  und 

ganz  leicht.     Es  hat  sie  Kirchhoff  in  seinen  Vorlesungen  iiber  Mechanik 

in  sehr  eleganter  Form  durchgeftihrt.     Man  findet  aus  dem  ersten  und 

zweiten  Keppler'schen  Gesetze,  dass  sie  fiir  jeden  Trabanten  zu  jeder  Zeit 

gegen  den  Centralkorper  gerichtet  und  dem  Quadrate  des  Abstandes  r 

k 
von  demselben  verkehrt  proportional,  also  in  der  Form  —  darstellbar  ist. 

Aus  dem  dritten  Keppler'schen  Gesetze  ergibt  sich  ausserdem,  dass  die 
Constante  k  von  Centralkorper  zu  Centralkorper  verschieden  ist,  aber 
fiir  alle  Trabanten  eines  und  desselben  Centralkorpers  denselben  Wert 
hat.  Da  wir  schon  bei  der  Schwere  die  Beschleunigung  als  das  mass- 
gebende  fiir  die  Bewegungsursache  oder  Kraft  erkannt  haben,  so 
wollen  wir  auch  hier  sagen,  der  Centralkorper  iibt  auf  jeden  Trabanten 
eine  Kraft  aus,  welche  die  Richtung  der  vom  iSIittelpunkte  des  Trabanten 
gegen  den  des  Centralkorpers  gezogenen  Geraden  hat  und  der  Lange 
dieser  Geraden  verkehrt  proportional  ist.  Diese  ist  einstweilen  sonst 
nichts  als  ein  anderer  Ausdruck  fiir  die  Thatsache  des  Vorhandenseins 
dieser  Beschleunigung.  Newton  hat  diesen  Satz  sofort  enorm  verallge- 
meinert  indem  er  annahm,  dass  iiberhaupt  jeder  Himmelskorper  auf  jeden 
andern  ja  jedes  materielle  Theilchen  auf  jedes  andere  eine  solche  Kraft 
ausiibt.  Wenn  daher  ein  Himmelskorper  mehreren  andern  so  nahe  ist, 
dass  er  von  ihnen  eine  merkliche  Einwirkung  erfahrt,  so  haben  wir  den 
Fall,  dass  er  gleichzeitig  aus  verschiedenen  Ursachen  verschiedene  Be- 
schleunigungen  nach  verschiedenen  Richtungen  erfahrt.  Da  wir  die 
Beschleunigung  durch  einen  Vector  dargestellt  haben,  so  ist  es  nicht  die 
einzig  notwendige,  aber  doch  bei  weitem  die  nahe  liegendste,  einfachste 
Annahme,  dass  sich  diese  Beschleunigungen  me  Vectoren  addiren.  In 
der  That  zeigt  sich,  dass  man  unter  dieser  Annahme  immer  Ubereinstim- 


Dritte  Vorlesimg.  295 

mung  mit  der  Erfahrung  erhalt.  Es  ergeben  sicli  die  Storungen  der  Plane- 
ten  untereinander,  der  Monde  durch  die  Sonne  und  durch  die  Planeten  in 
genauer  Ubereinstimmung  mit  der  Erfahrung.  Man  kann  jetzt  auch  den 
Horizont  erweitern  und  alle  Himmelskorper  auf  ein  und  dasselbe  mit 
dem  Fixsternhimmel  fest  verbundene  Coordinatensystem  beziehen  und 
erhalt  auch  die  Bewegung  der  Centralkorper  gegen  dieses  Coordinaten- 
system in  Ubereinstimmung  mit  der  Erfahrung.  Die  Schwere  erweist 
sich  als  identisch  mit  der  Anziehung  des  Erdkorpers  auf  den  schweren 
Korper.  Schliesslich  zeigen  die  Erscheinungen  der  Ebbe  und  Flut,  die 
Versuche  von  Cavendish,  Maskelyne,  Airy  etc.  die  Richtigkeit  der  Aus- 
dehnung  des  Newton'schen  Gesetzes  auf  die  irdischen  Korper.  Da  die 
wirkliche  Beschleunigung  immer  die  Vectorsumme  der  verschiedenen 
von  den  wirkenden  Korpern  erzeugten  Beschleunigung  ist,  so  folgt  jetzt 
als  spezieller  Fall  des  Newton'schen  Gesetzes,  dass  ein  Korper,  welcher 
von  alien  iibrigen  so  weit  entfernt  ware,  dass  keiner  derselben  eine  Wirk- 
ung  auf  ihn  ausiiben  wiirde,  zu  alien  Zeiten  die  Beschleunigung  Null 
erflihre.  Wir  erhalten  also  erst  jetzt  das  Tragheitsgesetz.  Selbstver- 
standlich  ist  hiemit  iiber  die  Ursache  der  Newton'schen  Kraft,  ob  die- 
selbe  eine  direkte  Fernwirkung  ist  oder  durch  ein  Medium  vermittelt 
wird,  nicht  das  mindeste  prajudicirt.  Wir  konnten  auch  jetzt  schon  den 
Begriff  der  Masse  ableiten.  Die  Massen  zweier  Centralkorper  wiirden 
sich  ja  wie  die  ihnen  entsprechenden  Werte  der  Constanten  h  des  Gravi- 
tationsgesetzes  verhalten  und  durch  den  Cavendish'schen  Versuch  konnte 
diese  Definition  auch  auf  irdische  Korper  ausgedehnt  werden.  AUein  wir 
wiirden  da  die  Proportionalitat  der  Constante  k  mit  der  als  Tragheits- 
widerstand  definirten  Masse  vorwegnehmen,  was  offenbar  ein  logischer 
Fehler  ware.  Wir  miissen  daher  zum  Begriff e  der  Masse  auf  ganz  an- 
derem  Wege  zu  gelangen  suchen.  Wir  haben  bisher  als  das  Massge- 
bende  fiir  die  Kraft  die  Beschleunigung  betrachtet.  Es  konnte  nun  als 
das  einfachste  erscheinen,  die  Grosse  der  Beschleunigung,  welche  ein 
Korper  durch  einen  andern  erfahrt,  einfach  als  die  Grosse  der  Kraft  zu 
bezeichnen,  welche  der  letztere  auf  den  ersteren  ausiibt.  Es  geschieht 
dies  auch  manches  Mai  und  man  bezeichnet  die  so  definirte  Kraft  als  die 
beschleunigende  Kraft.  Allein  im  AUgemeinen  ist  es  besser  einen  andern 
Begriff  einzufiihren.  Wir  denken  namlich  beim  Worte  Kraft  in  erster 
Linie  an  die  Muskelanstrengungen,  welche  wir  ausiiben  konnen.  Nun 
liegt  freilich  kein  Grund  vor,  ja  es  ware  ganz  verkehrt  anzunehmen,  dass 
jedes  Mai,  wenn  unbelebte  Korper  Krafte  aufeinander  ausiiben  etwas 


296  Ludwig  Boltzmann  : 

vorhanden  sein  miisse,  was  diesen  Muskelanstrengungen  irgendwie  ent- 
spricht.  AUein  es  wird  sich  doch  empfehlen,  wenn  wir  die  Bezeich- 
nungen  so  walilen,  dass  sie  sich  den  durch  diese  Muskelanstrengungen 
erworbenen  Begriffen  moglichst  gut  anschliessen.  Wir  sahen,  dass  alle 
Korper  durch  die  Schwere  die  gleiche  Beschleunigung  erfahren.  Wiirden 
wir  nun  diese  ohne  weiteren  Factor  als  Mass  der  Kraft  wiihlen,  so  wiire 
die  Kraft,  welche  die  Schwere  auf  sie  ausiibt,  (das  Gewicht)  fiir  alle 
Korper  dasselbe.  Nun  lehrt  aber  die  tagliche  Erfahrung,  dass  die  Mus- 
kelanstrengung  welche  wir  brauchen,  um  den  Fall  aufzuheben,  fiir  ver- 
schiedene  Korper  sehr  verschieden  ist.  Wollen  wir  daher  mit  unseren  Vor- 
stellungen  im  Einklang  bleiben,  so  miissen  wir  sagen,  dass  auch  die  Schwere 
auf  die  verschiedenen  Korper  sehr  verschiedene  Kriifte  ausiibt,  dass  aber 
die  Korper  von  grosserem  Gewichte  dieser  beschleunigenden  Wirkung  der 
Schwere  einen  grosseren  Widerstand,  den  Tragheitswiderstand,  die  Masse, 
entgegensetzen,  so  dass  erst  in  folge  beider  Umstande  zusammen  alle 
Korper  die  gleiche  Beschleunigung  erfahren.  Um  die  Masse  in  dieser 
Weise  als  Tragheitswiderstand  zu  defiuiren,  miissen  wir  an  verschiedene 
Korper  die  gleiche  Kraft  anbringen.  Das  Verbal tnis  ihrer  Massen  kon- 
nen  wir  dann  als  das  verkehrte  Verhaltnis  der  Beschleunigungen  defi- 
niren,  die  sie  durch  gleiche  Krafte  erhalten.  Aber  darin  liegt  eben  die 
grosste  Schwierigkeit  wie  man  die  Gleichheit  der  Krafte,  wenn  diese  auf 
verschiedene  Korper  wirken,  ohne  logischen  Fehler  feststellen  soil.  Man 
konnte  zwei  Korper  dem  Zuge  gleich  beschaffener  gleich  gespannter 
Schniire  oder  elastischer  Federn  unterwerfen.  Allein  da  miisste  man 
erst  durch  complicirte  der  Erfahrung  entnommene  Argumente  als  wahr- 
scheinlich  hinzustellen  suchen,  dass  gleich  beschaffene  Schniire  auf  zwei 
ganz  verschiedene  Korper  dieselben  Krafte  ausiiben,  was  gewiss  nicht 
a  priori  evident  ist.  Wir  konnten  auch  nach  Mach  einfach  den  Satz 
der  Gleichheit  der  Wirkung  und  Gegenwirkung  postuliren.  Wenn  dann 
bloss  zwei  Korper  in  Wechselwirkung  begriffen  sind,  so  ware  die  Gleich- 
heit der  Krafte,  welche  auf  beide  Korper  wirken  evident.  Wenn  sie  sich 
zudem  nur  Parallelverschiebungen  ertheilen,  so  ware  das  Verhaltnis 
ihrer  Massen  einfach  zu  definiren,  als  das  verkehrte  Verhaltnis  der  Be- 
schleunigungen, welche  an  ihnen  zu  beobachten  sind.  Allein  bei  der 
Wirkung  dazwischen  gebrachter  Schniire,  Faden  etc.  haben  wir  eigent- 
lich  schon  immer  mehr  als  zwei  in  Wechselwirkung  begriffeue  Korper 
und  es  wiirde  auch  die  Deformation  dieser  Zwischenkorper  in  Betracht 
zu  Ziehen  sein.     Der  von  Mach  ansrenommene  Fall  konnte  also  in  reiner 


Dritte  Vorlesimg.  297 

Weise  eigentlich  nur  bei  directer  Fernwirkung  vorkommen  und  es  ware 
sehr  misslich,  wenn  man  vom  rein  empirisclien  Standpunkte  aus  die 
directe  Fernwirkung  a  priori  annehmen  miisste.  Streintz  sucht  eine 
einwurfsfreie  Definition  in  folgender  Weise  zu  gewinnen,  Er  denkt 
sich  irgend  ein  System  beliebiger  Korper.  In  demselben  kommen  zwei 
Korper  K^  und  K^  vor.  Diese  ruhen  im  ersten  Augenblicke  und  beginnen 
sich  dann  mit  Beschleunigung  aber  jeder  parallel  zu  sich  selbst  zu  be- 
wegen.  Es  soil  nun  die  Bewegung  beider  Korper  dadurch  aufgehoben 
werden  konnen,  dass  man  sie  starr  mit  einander  verbindet.  Dies  ver- 
wendet  er  als  Kriterium,  dass  friiher  auf  jeden  genau  die  gleiche  Kraft 
wirkte,  well  sich  beide  Krafte  durch  blosse  starre  Verbindung  jetzt  auf- 
heben.  Er  nennt  diese  Begriffsbestimmung  der  Gleichheit  der  Kraft  die 
statische.  Sie  hat  das  fiir  sich,  dass  sie  das  Princip  der  Gleichheit  der 
Wirkung  und  Gegenwirkung  involvirt,  wie  man  sofort  sieht,  wenn  man 
den  speziellen  Fall  betrachtet,  dass  das  ganze  System  bloss  aus  den  zwei 
auf  einander  wirkenden  Korpern  K^  und  K^  besteht.  Sie  hat  aber  doch 
audi  manches  Willkiirliche.  Dass  durch  die  starre  Verbindung  die  Wirk- 
ung der  librigen  Krafte  nicht  gestort  wird,  kann  wieder  hochstens 
erfahrungsmassig  wahrscheinlich  gemacht  werden.  Dass  die  Verbin- 
dungskrafte  sich  zu  den  librigen  addiren,  setzt  schon  gewisse  Satze  der 
Statik  voraus.  Noch  grosser  wiirden  die  Schwierigkeiten,  wenn,  die 
Korper  K^  und  K^  anfangs  in  Bewegung  begriffen  wJiren.  WoUte  man 
da  nicht  von  vornherein  annehmen,  dass  die  Krafte  bloss  von  der  rela- 
tiven  Lage  abhangen,  durch  den  aus  der  plotzlichen  starren  Verbindung 
resultirenden  Stoss  nicht  gestort  werden  und  Ahnliches,  so  miisste  ihre 
Beschleunigung  durch  eine  die  Bewegung  gestattende  und  auf  beide 
Korper  bloss  beschleunigend  wirkende  plotzlich  eingeschaltete  Feder 
aufgehoben  werden.  Halt  man  einmal  an  der  Streintz'schen  Vorstellung 
fest,  so  hat  die  Definition  der  Massenverhaltnisses  weiter  keine  Schwierig- 
keit.  Die  Massen  der  beiden  Korper  K^  und  K^  verhalten  sich  dann 
umgekehrt,  wie  die  Beschleunigungen,  die  sie  im  ersten  Falle,  wo  keine 
starre  Verbindung  vorhanden  war,  erhielten,  da  ja  damals  auf  beide 
gleiche  Krafte  wirkten.  Natiirlich  ist  sowohl  bei  der  Mach'schen  als  bei 
der  Streintz'schen  Definition  noch  immer  erforderlich,  sich  auf  besondere 
Erfahrungssatze  zu  berufen,  vermoge  welcher  das  Massenverhaltnis 
zweier  Korper  immer  gleich  ausfallt,  unter  was  immer  fiir  Umstanden 
man  den  hiezu  dienenden  Versuch  angestellt  haben  mag  und  vermoge 
welcher  das  Verhaltnis  der  Massen  der  Korper  K^  and  K^  stets  gleich 


298  Luclwig  Boltzmann  : 

dem  Producte  der  beiden  Massenverhaltnisse  der  Korper  K-^^  K^  und  K^^ 
K^  ist. 

Zii  bemerken  ist  noch,  dass  wir  nur  das  Verhaltnis  zweier  Massen  bisher 
definirt  haben.  Um  die  Masse  durch  eine  Zahl  auszudriicken,  miissen 
wir  irgend  eine  Masse  willkiiiiich  als  eine  neue  Einheit  wahlen.  Von 
alien  Grossen,  welche  daher  durch  Zalilen  ausgedriickt  werden,  deren 
Grosse  von  der  Wahl  der  Masseneinheit  abhangig  ist,  werden  wir  sagen 
dass  sie  gewisse  Diinensionen  beziiglich  der  Masse  haben.  Haben  wir  den 
Begriff  der  Masse  in  der  einen  oder  andern  Weise  festgestellt,  so  hat  die 
Definition  der  Kraft  im  gewohnlichen  Sinne  oder  wie  man  auch  sagt,  der 
bewegenden  Kraft  keine  Schwierigkeit  mehr.  Dieselbe  ist  das  Product 
der  Masse  in  die  Beschleunigungen  und  hat  daher  beziiglich  der  Masse 
die  Dimension  eins.  Da  sich  die  Beschleunigungen  wie  Vectoren  addi- 
ren,  so  gilt  dies  auch  von  den  Kraften,  wenigstens  insoweit  wir  diese 
bisher  betrachtet  haben.  Dieser  Satz  vom  Kraftenparallelogramm  sowie 
die  iibrigen  bisher  entwickelten  Satze,  konnen  nun  auch  auf  die  Statik 
und  Dynamik  der  durch  gespannte  Faden  oder  durch  Federn  erzeugten 
Druck  und  Zugkrafte  iibertragen  werden.  Natiirlich  zunachst  bloss  in 
dem  idealen  Falle,  dass  die  Bewegung  der  einzelnen  Theile  der  Faden  und 
Federn  nicht  betrachtet  wird  und  dass  die  bewegten  Korper  sich  stets 
parallel  zu  sich  selbst  bewegen.  Es  konnte  so  z.  B.  die  Mechanik  der 
Atwood'schen  Fallmaschine  mit  Hilfe  des  bisher  Entwickelten  ohne 
weiteres  discutirt  werden. 

Aus  dem  Umstande,  dass  sich  das  Newton'sche  Gravitationsgesetz  in 
symetrischer  Weise  beziiglich  beider  wirkender  Korper  aussprechen  muss 
und  dass  die  Anziehungsconstante  K  fiir  alle  Trabanten  desselben  Cen- 
tralkorpers  gleich  ist,  leitet  man  leicht  ab,  dass  diese  gleich  dem  Producte 
der  Massen  der  beiden  wirkenden  Korper  in  eine  fiir  das  ganze  Universum 
constante  Grosse  sein  muss,  wahrend  die  Thatsache,  dass  alle  Korper 
durch  die  Schwere  die  gleiche  Beschleunigung  erhalten,  schon  lehrt,  dass 
das  Gewicht  der  Masse  proportional  sein  muss. 

AVir  sind  aber  noch  sehr  weit  davon  entfernt  aus  den  bisher  entwickel- 
ten Grundlagen  sammtliche  Siitze  der  Mechanik  ableiten  zu  konnen. 
Wir  haben  ja  bisher  bloss  die  Bewegung  eines  festen  Korpers  parallel  zu 
sich  selbst  betrachtet  und  haben  den  wichtigen  Begriff  des  Angriffspunk- 
tes  einer  Kraft  noch  gar  nicht  gewonnen.  Um  diesen  zu  erhalten,  um  die 
Drehung  der  starren  Korper,  die  Deformationen  der  elastischen  und  die 
Bewegungen  der  fliissigen  behandeln  zu  konnen,  miissen  wir  von  neuen 


Dritte  Vorlesung.  299 

Thatsachen  ausgehen.  Wenn  ein  Faden  an  einem  Korper  befestigt  ist 
oder  eine  Feder  auf  eine  einzige  Stelle  desselben  driickend  wirkt,  so  gibt 
es  stets  eine  ganz  kleine  Partie  des  Korpers,  welche  zunachst  von  der 
Kraft  afficirt  wird.  Losen  wir  diese  los  und  stellen  einen  kleinen 
Zwischenraum  zwisclien  ihr  und  den  iibrigen  Theilen  des  Korpers  her, 
so  wird  derselbe  erst  wieder  afficirt,  wenn  dieser  Zwischenraum  durch 
die  Bewegung  des  kleinen  abgetrennten  Theiles  sicli  ausgefiillt  hat. 
Wir  nennen  daher  diesen  Theil  die  Angriffstelle  und  konnen  sie  wieder 
zu  einem  Angriffspunkte  idealisiren.  Wir  mlissen  nun  noch  die  bekann- 
ten  Satze  iiber  die  Versetzbarkeit  von  Kraften  an  starren  Korpern  als 
idealisirte  Erfahrungsthatsachen  beifiigen.  Mittelst  derselben  konnen 
wir  dann  in  ebenfalls  hinlanglich  bekannter  Weise  die  Satze  iiber  das 
Gleichgewicht  von  beliebigen  Kraften,  welche  auf  einen  starren  Korper 
wirken,  die  Satze  von  den  statischen  Momenten  ableiten.  Wir  schlagen 
hier  insoferne  einen  analogen  Weg  ein,  wie  Streintz  bei  der  Definition 
der  Masse,  als  wir  von  der  Statik  ausgehen  und  erst  von  dieser  zur 
Dynamik  gelangen.  Die  Satze  von  den  statischen  Momenten  haben  wir 
da  freilich  zunachst  bloss  fiir  eine  begrenzte  Zahl  von  Kraften  bewiesen, 
von  denen  jede  nur  auf  einen  einzelnen  Punkt  des  Korpers  wirkt.  Wir 
miissen  dazu  noch  die  Annahme  hinzufiigen,  dass  man  im  Falle,  wo  die 
Krafte  den  Korper  oder  einen  ausgedehnten  Theil  desselben  als  Gauzes 
anfassen  die  Sache  immer  so  ansehen  kann,  als  ob  sie  auf  sehr  viele 
respective  unendlich  viele  Punkte  seiner  Oberflache  oder  seines  Innern 
gerade  so  wirken  wtirden,  als  ob  an  jedem  dieser  Punkte  eine  ein  wenig 
gespannte  Schnur  oder  eine  ein  wenig  driickende  Feder  befestigt  ware. 
So  muss  mann  z.  B.  von  der  Schwere  annehmen,  das  sie  gleichmassig 
auf  alle  Punkte  des  schweren  Korpers  wirkt.  Einen  andere  Weg,  auf 
welchem  man  den  Ubergang  von  der  Bewegung  parallel  zu  sich  selbst 
zur  Drehbewegung  versuchen  konnte,  will  ich  hier  nur  ganz  kurz 
andeuten.  Wir  konnen  aus  dem  Principe  der  Erhaltung  der  lebendigen 
Kraft  folgenden  Satz  ableiten.  Wenn  auf  einen  festen  Korper  eine  Kraft 
wirkt,  die  ihn  nur  parallel  zu  sich  selbst  zu  bewegen  sucht,  so  muss 
immer  eine  ihrer  Richtung  parallele  Gerade,  welche  wir  die  Angriffslinie 
nennen  woUen,  von  soldier  Beschaffenheit  existiren,  dass  wenn  man  einen 
beliebigen  Punkt  des  festen  Korpers,  welcher  auf  derselben  liegt,  festhalt, 
der  Korper  ins  Gleichgewicht  kommen  muss.  In  gleicher  Weise  kann 
man  beweisen,  dass,  wenn  zwei  feste  Korper  K^  und  K^  so  in  Wechsel- 
wirkung  begriffen  sind,  dass  jeder  dem  andern  nur  eine  Bewegung  parallel 


Boo  Ludwig  Boltzmann  : 

zu  sich  selbst  ertheilt,  Wirkung  und  Gegenwirkung  gleich  sein  muss  und 
die  Angriffslinien  zusammenfallen  mlissen.  Denkt  man  sich  dann  einen 
Punkt  A  der  gemeinsamen  Angriffslinien  festgehalten,  so  muss  das  ganze 
System  ins  Gleichgewicht  kommen.  Jeden  solchen  Punkt  konnen  wir  als 
Angriffspunkt  der  Kraft  betrachten.  An  diesen  Begriff  des  Angriffs- 
punktes,  konnen  dann  ebenfalls  die  Siitze  von  den  statischen  Momenten 
gekniipft  werden. 

Hat  man  einmal  diese  Siitze  so  oder  so  gewonnen,  so  muss  man  zur 
Zerlegbarkeit  der  Korper  in  Volumelemente  libergehen.  Man  fiihrt 
wieder  als  Erfahrungssatz  an,  dass  sehr  viele  Korper,  wenigstens  mit 
geniigender  Anniiherung  in  zwei  Korper  von  je  der  halben  Masse  zerlegt 
werden,  wenn  man  sie  in  zwei  Theile  von  gleichem  Volumen  zerschneidet. 
Analog,  wenn  man  sie  in  drei  gleiche  Theile  theilt  u.  s.  f.  Denkt  man 
sich  dies  ins  Unendliche  fortgesetzt,  so  gelangt  man  zu  einem  Satze, 
den  man  dahin  aussprechen  kann  dass  diese  Korper  aus  unendlich  vielen 
Volumelementen  dv  bestehen  und  die  in  jedem  Volumelemente  enthaltene 
Masse  dm  =  pdv  ist.  Bei  andern  inhomogenen  Korj^ern  gilt  dies  wenig- 
stens nahezu  fiir  jeden  kleinen  Volumtheil  des  Korpers,  so  dass  wir  die- 
selbe  Formel  anwenden  konnen,  wenn  wir  p  als  von  Punkt  zu  Punkt 
veriinderlich  betrachten. 

Was  nun  die  Krafte  anbelangt,  welclie  die  Volumelemente  fester 
Korper  aufeinander  ausliben,  so  muss  man  annehmen,  dass  jedes  Volum- 
element  nur  auf  die  unmittelbar  benachbarten  wirkt  und  dass  es  auf  alle 
der  Trennungsflache  anliegenden  Punkte  Krafte  ausiibt,  welche  gerade 
so  wirken,  als  ob  daran  ziehende  gespannte  Fiiden  oder  driickende,  auf- 
gestiitzte  Stabe  befestigt  waren.  Wenn  die  Trennungsflache  eben  und 
geniigend  klein  ist,  so  muss  man  zudem  annehmen,  dass  diese  Krafte 
gleichmassig  auf  alle  der  Trennungsflache  anliegenden  Punkte  wirken. 
Diese  Satze  konnen  wol  kaum  direct  erfahrungsmassig  bestatigt  werden 
und  finden  ihre  Rechtfertigung  nur  in  der  nachherigen  Ubereinstimmung 
der  aus  ihnen  entwickelten  Siitze  mit  der  Erfahrung.  Wendet  man  den 
Satz  von  den  statischen  Momenten  auf  ein  Volumelement  an,  so  findet 
man,  dass  im  Falle  des  Gleichgewichtes  die  auf  ein  zur  a:-axe  senkrechtes 
Fliichenelement  in  der  ?/-Richtung  wirkende  Kraft  gleich  sein  muss  der 
auf  ein  gleiches  zur  ?/-Richtung  senkrechtes  Fliichenelement  in  der 
a;-Richtung  wirkenden  Kraft,  was  wir  den  Satz  X  nennen  wollen.  Zu 
den  bisher  aufgestellten  Annahmen  welche  Avir  uns  als  durch  die  Erfahr- 
ung geniigend  motivirt  dachten,  sind  noch  die  folgenden  hinzuzunehmen. 


Dritte  Vorlesung.  301 

Erstens,  die  elastische  Kraft  ist  bloss  von  der  augenblicklichen  Gestaltver- 
anderung  des  betreffenden  Korpers,  nicht  von  den  friiheren  Zustanden 
desselben,  noch  auch  von  der  Geschwindigkeit  seiner  Theilchen  abhangig. 
Zweitens,  jedes  Volumelement  bewegt  sich  nach  den  Gesetzen,  welche  wir 
bisher  bloss  fiir  die  Bewegung  parallel  zu  sich  selbst  abgeleitet  haben. 
Unter  diesen  Annalimen  erhalt  man  dann  sofort  die  Gleichungen  der 
gewobnliclien  Elasticitiitslehre.  Dieselben  gelten  natiirlich  wieder  nur 
fiir  einen  idealen  festen  Korper,  alle  festen  Korper  zeigen  innere  Reibung 
und  elastische  Nachwirkung,  welche  wir  bisher  ausgeschlossen  haben. 
Auch  der  Satz,  welchen  wir  den  Satz  X  nannten,  ist  keineswegs  a  priori 
evident.  Lord  Kelvin  hat  sich  einmal  den  Lichtather,  sonst  ganz  mit  den 
Eigenschaften  begabt  gedacht,  welche  wir  an  festen  Korpern  wahrnehmen, 
nur  dass  er  die  Richtigkeit  dieses  Satzes  X  fallen  liess.  Wir  woUen  uns 
hier  nicht  in  eine  Discussion  einlassen  ob  durch  die  Annahme  Lord 
Kelvins  das  Verhalten  des  Lichtathers  erkliirt  werden  kann.  Es  geniigt 
uns,  dass  derselbe  ohne  alle  inneren  Widersprliche  Bewegungsgleichungen 
fiir  die  Volumelemente  eines  festen  Korpers  ausarbeiten  konnte,  fiir 
welchen  der  Satz  X  nicht  gilt.  Wir  wollen  jedoch  vorliiufig  bei  Korpern 
stehen  bleiben,  welche  den  idealen  Gleichungen  der  Elasticitatslehre 
geniigen.  Wenn  solche  Korper  so  wenig  deformirbar  sind,  dass  man  sie 
als  Starr  betrachten  kann  und  wenn  durch  beliebige  Systeme  derselben 
beliebige  Bedingungsgleichungen  realisirt  sind,  so  kann  man  jetzt  leicht 
nachweisen,  dass  fiir  dieselben  das  vereinigte  Princip  der  virtuellen 
Geschwindigkeiten  und  d'Alembert's  gelten  muss.  Denn  wenn  man 
alle  Krafte  auch  die  elastischen  ins  Auge  fasst,  so  verschwindet  jedenfalls 
die  Summe 


a 


(.g-x)i»t(.5-i')%+(,g-z)s.; 


da  jedes  Glied  dieser  Summe  einzeln  verschwindet.  Da  aber  die  Wirkung 
immer  gleich  der  Gegenwirkung  ist,  so  miissen  die  Glieder  dieser  Summe, 
welche  sich  auf  die  Wechselwirkung  der  Volumelemente  beziehen  separat 
verschwinden,  wenn  diese  starren  Korpern  angehoren  also  keiner  relativen 
Lagenanderung  fahig  sind,  wahrend  bei  bloss  einseitigen  Verbindungen 
die  bekannten  Ungleichungen  abgeleitet  werden  konnen.  Dies  kann 
auch  auf  Verbindungen  iibertragen  werden,  die  nur  theilweise  starr  sind 
z.  B.  unausdehnsame  Flachen,  Faden  etc. ;  denn  diese  konnen  immer  als 
Grenzfall  sehr  diinner  elastischer  Korper  betrachtet  werden.     Man  erhalt 


302  Ludwig  Boltzmann  : 

so  das  vereinigte  Princip  der  virtuellen  Verschiebungen  und  d'Alembert's 
in  der  gewohnlichen  Form.  Erst  aus  diesem  Principe  konnen  wir  jetzt 
die  Satze  von  der  Bewegung  des  Schwerpunkts,  vom  Triigheitsmomente 
etc.  ableiten.  Diese  Siitze  erscheinen  daher  in  unserem  Systeme  erst  an 
dieser  Stelle.  Es  kann  dies  nicht  anders  sein  ;  denn  darin  besteht  ja  das 
Wesen  der  inductiven  Methode,  dass  wir  nicht  den  Begriff  des  materiellen 
Pimktes  als  eines  unausgedehnten  mit  Masse  begabten  Korpers  postuliren, 
sondern  die  Schliisse,  welche  man  sonst  mit  Hilfe  dieses  Begriffes  macht, 
erst  ausfiihren,  wenn  wir  zur  Vorstellung  des  Volumelementes  gekommen 
sind,  welche  wir  eher  der  Erfahrung  entnehmen  zu  konnen  glauben,  als 
die  des  materiellen  Punktes.  Wir  konnen  dann  diese  Siitze  erst  erhalten, 
wenn  wir  die  Wechselwirkung  der  Volumelemente  behandelt  haben. 
Wir  mussten  freilich  schon  friiher  an  zwei  Stellen  vom  Begriffe  des 
mathematischen  Punktes  Gebrauch  machen,  namlich  als  wir  die  Beweg- 
ung eines  einzigen  hervorgehobenen  Punktes  eines  Korpers  betrachteten 
und  als  wir  Krafte  fingirten,  welche  an  einem  einzigen  Punkte  eines 
Korpers  angreifen.  AUein  da  war  die  Abstraction  doch  viel  einfacher 
und  klarer,  als  wenn  wir  das  Ideal  eines  unausgedehnten  mit  Masse 
begabten  Korpers  bilden  und  dessen  Drehung  einfach  vernaclilassigen, 
ohne  dass  wir  die  Gesetze  der  Drehung  vorher  kennen  gelernt  haben. 
Manche  Satze  konnten  wir  allerdings  auch  auf  einem  andern  als  dem 
eingeschlagenen  Wege  gewinnen.  Ein  Analogon  des  Schwerpunktsatzes 
konnten  wir  z.  B.  ableiten,  indem  wir  ein  System  von  ausgedehnten 
Korpern  betrachten  wiirden,  zwischen  denen  innere  Krafte  thatig  sind 
und  auf  welche  auch  aussere  Krafte  wirken,  welche  ihnen  aber  alle  nur 
Bewegungen  parallel  zu  sich  selbst  ertheilen.  Nimmt  man  dazu  noch  die 
Annahme,  dass  fiir  die  innere  Krafte  Wirkung  und  Gegenwirkung  immer 
gleich  ist,  so  wiirde  ein  dem  Schwerpunktsatze  ahnlicher  Satz  flir  ein 
solches  System  in  Wechselwirkung  begriffener  ausgedehnter  Korper 
folgen. 

Die  Krafte,  welche  in  Fliissigkeiten  wirken,  konnen  als  ein  spezieller 
Fall,  der  in  elastischen  Korpern  wirkenden  betrachtet  werden  und  sie 
konnen  daher  ebenfalls  nach  der  im  bisherigen  auseinandergesetzten 
Methode  gewonnen  werden.  Die  Gestaltanderungen  der  Fliissigkeiten 
konnen  dann  durch  die  Bewegung  der  Volumtheile  derselben  dargestellt 
werden,  welche  die  entwickelten  Gesetze  befolgt ;  nur  dass  die  Deforma- 
tion des  Korpers  als  Ganzes  jetzt  eine  beliebig  grosse  sein  kann. 

Wir  haben  hiemit  das  Gebiet  der  eigentlichen  mechanischen  Erschein- 


Dritte  Vorleswig.  303 

ungen  erschopft.  Bei  den  dissipativen  Erscheinungen  (elastische  Nach- 
wirkung,  Reibung  etc.)  spielt  bereits  die  entwickelte  Warme  eine  Rolle. 
Wir  konnen  natiirlich  die  Form  der  friihern  Gleicliungen  wahren,  indem 
wir  zu  den  bisher  abgeleiteten  Kraften  noch  Glieder  von  solcher  Be- 
schaffenheit  hinzu  addiren,  dass  deren  Summe  genau  gleich  dem  Werte 
der  mit  der  Masse  multiplicirten  Besclileunigung  wird.  Diese  Zusatz- 
glieder  konnen  wir  dann  immer  als  Reibungskraft,  Mittelswiderstands- 
kraft  etc.  bezeichnen,  doch  hat  diese  Darstellung  einen  rein  formalen 
Wert,  wenn  die  Zusatzglieder  in  ganz  complicirter  Weise  von  der 
Bewegungsgeschwindigkeit,  den  friihern  Zustanden  etc.  abhangen.  Es 
bietet  die  Molekulartheorie  da  entschieden  mehr  Anschaulichkeit,  da  sie 
die  Zusatzglieder  doch  durch  langsame  Drehung  der  Molekiile  in  neue 
Ruhelagen,  Umsetzung  der  sichtbaren  Bewegung  in  Molekularbewegung 
etc.  einigermassen  versinnlichen  kann.  Das  Princip  der  virtuellen  Ver- 
schiebung  behalt  dann  natiirlich,  so  lange  es  auf  das  Gleichgewicht 
ruhender  Korper  angewendet  wird,  seinen  Sinn,  da  bei  der  Ruhe  dissipa- 
tive  Vorgange  fehlen.  Aber  das  d'Alembert'sche  Princip  ist  auch  zu 
einer  leeren  Formel  herabgesunken,  so  bald  sich  in  den  Ausdriicken  fiir 
die  Kriifte  Glieder  finden,  welche  selbst  wieder  von  der  Bewegung,  von 
den  vorhergegangenen  Zustanden  der  Korper  etc.  abhangen.  Uber  die 
Darstellung  der  elektrischen  und  magnetischen  Erscheinungen  will  ich 
hier  nur  bemerken,  dass  dieselbe  ebenfalls  in  die  Form  der  mechanischen 
Gleichungen  gebracht  werden  kann  und  muss,  sobald  diese  Erscheinungen 
von  Bewegungen  ponderabler  Korper  begleitet  sind.  Des  Naheren  hier- 
auf  einzugehn,  ist  jedoch  nicht  meine  Absicht. 

Ich  woUte  in  dem  Bisherigen  keineswegs  eine  consequente  in  sich 
abgeschlossene  Darstellung  der  Mechanik  vom  inductiven  Standpunkt 
geben.  Ich  woUte  vielmehr  bloss  die  Wege  andeuten,  auf  denen  eine 
solche  vielleicht  gewonnen  werden  konnte  und  namentlich  die  Schwierig- 
keiten  aufdecken,  mit  denen  ihre  Durchfiihrung  verkniipft  ist,  wenn  man 
sich  bestrebt,  das  innere  Bild  ebenso  klar  hervortreten  zu  lassen  und 
consequent  durchzuflihren,  wie  dieses  bei  der  deductiven  Behandlung 
moglich  ist.  Ich  komme  daher  zu  dem  Resultate,  dass  unter  den  bis- 
herigen Darstellungsversuchen  der  Mechanik  die  deductiven,  wie  die  von 
Hertz  und  die  von  mir  in  meinem  citirten  Buche  gemachte  vorzuziehen 
seien.  Da  aber  diese  deductive  Darstellung  wie  schon  zu  Anfang 
gezeigt  wurde,  den  Mangel  hat,  dass  sie  so  lange  Zeit  hindurch  gar 
nicht  an  die  Erfahrung  ankniipft  und  vielfach  den  Schein  des  Willkiir- 


304 


Ludwig  Boltzmann : 


lichen  erweckt,  so  wiirde  es  mich  sehr  freuen,  wenn  es  jemanden  gelange, 
der  deductiven  Darstelluug  eiue  inductive  an  die  Seite  zu  stellen,  welche 


gleich  einfach  und  naturgemass  vorginge  und  doch  das  innere  geistige 
Bild  in  gleicher  Deutlichkeit  und  Consequenz  hervortreten  liesse.      Es 


Vierte  Vorlesung.  305 

ware  dies  wohl  in  einer  kurzen  Abhandlung  kaum  moglich,  soudern  nur  in 
einem  grosseren  Buche,  wo  man  den  Grundprincipien  sogleich  die  An- 
wendung  auf  alle  speziellen  Fiille  folgen  lassen  konnte.  Denn  erst  an  der 
Moglichkeit  der  exacten  Darstellung  aller  moglichen  speziellen  Fiille 
erprobt  sich  die  Klarheit  und  Consequenz  der  Bilder,  wie  sich  das  am 
besten  an  der  Hertz'schen  Darstellung  zeigt,  wo  diese  Anwendung  auf 
spezielle  Fiille  fehlt.  Sollten  sich  aber  die  Liicken,  die  sich  in  meiner 
gegenwartigen  Darstellung  finden,  nicht  ausfiillen  lassen,  so  wiirde  mich 
auch  dies  freuen,  denn  es  wiirde  den  definitiven  Sieg  der  deductiven  iiber 
die  inductive  Behandlungsweise  bedeuten.  Ich  mochte  gewissermassen 
die  Vertreter  der  inductiven  Richtung  einladen,  alle  Fehler,  die  sich  in 
meiner  gegenwartigen  Darstellung  finden  aufzudecken,  die  Moglich- 
keit der  genauen  Durchfiihrung  aller  Schlussweisen,  die  ich  hier  nur 
kurz  angedeutet  habe,  zu  zeigen  und  ihre  besten  Kriifte  einzusetzen  in 
dem  Wettkampfe  mit  der  deductiven  Darstellung,  damit  beide  mit  ein- 
ander  verglichen  werden  konnen  und  sich  im  Wettstreite  stets  ausbilden 
und  vervoUkommnen. 

Da  der  Energiebegriff  nicht  nur  in  der  Mechanik,  sondern  in  der 
ganzen  Naturwissenschaft  eine  so  wichtige  RoUe  spielt,  so  waren  auch  con- 
sequente  Darstellungen  der  Grundprincipe  der  Mechanik  vom  Standpunkte 
der  Energetik  hochst  erwiinscht,  welche  also  nicht  von  den  Begriffen  der 
Beschleunigung  und  Kraft  sondern  von  denen  der  lebendigen  Kraft  und 
des  Potentiales  auszugehen  hatten.  Doch  miissten  die  betreffenden 
Bilder  auch  nach  der  deductiven  oder  inductiven  Methode  durchaus  klar 
consequent  und  einwurfsfrei  entwickelt  werden  und  es  miissten  vollkom- 
men  pracise  Regeln  gegeben  werden,  wie  dieselben  eindeutig  auf  alle 
speziellen  Falle  anzuwenden  sind,  ohne  dass  die  Kenntnis  der  alten 
Mechanik  dabei  vorausgesetzt  wird. 

ViEETE   VOKLESUNG. 

Die  vierte  Vorlesung  begann  der  Vortragende  mit  der  Vorzeigung  des 
Modells  fiir  die  Maxwell'sche  Theorie  der  Elektricitiit  und  des  Magnetis- 
mus,  welches  in  dessen  Buch  ^^Vorlesungen  iiber  Maxwells  Theorie  der 
Elektricitiit  und  des  Lichtes  erster  Theil  "  beschrieben  ist.  Es  wurden 
alle  dort  erwahnten  Experimente  mit  gutem  Erfolge  durchgefiihrt. 
Hierauf  gab  er  noch  folgende  Ubersicht  iiber  die  das  Princip  der  kleins- 
ten  Wirkung  und  das  Hamilton'sche  Princip  umfassenden  Gleichungen. 


306  Ludwig  Boltzmann: 

Wenn  wir  die  FiiUe  einseitiger  Verbindungen  ausschliessen,  so  wird 
das  vereinigte  Princip  der  virtuellen  Verscliiebungen  uud  d'Alemberts, 
wie  wir  sahen  durch  eine  Gleichung  ausgedriickt,  welche  wir  erhalten, 
wenn  wir  den  Ausdriick  auf  Seite  36  gleich  Null  setzen.  Fiibrt  man 
darin  generalisirte  Coordinaten  ein  und  setzt  Einfachheit  halber  voraus, 
dass  eine  Kraftfunction  V  besteht,  welche  aber  die  Zeit  enthalten  kann, 
so  transformirt  sich  dieselbe  in  folgende  Gleichung 

dt       dp       dp 

wobei  p  irgend  eine  generalisirte  Coordinate,  q  das  dazu  gehorige  Mo- 
ment, T  die  gesammte  kinetische  Energie  ist.  Wenn  jede  beliebige 
Coordinate  p  zu  jeder  beliebigen  Zeit  t  eine  beliebige  Variation  Sp  erfahrt, 
so  kann  man  die  letzte  Gleichung  mit  8p  multipliciren  und  beztiglich  aller 
p  summiren.  Im  speciellen  Falle,  dass  alle  8p  integrable  Functionen  der 
Zeit  sind,  kann  man  noch  mit  dt  multipliciren  und  iiber  eine  beliebige 
Zeit  (von  tQ  bis  <)  integriren  ;  nach  partieller  Integration  der  dq/dt  ent- 
haltenden  Glieder  folgt  in  dieser  Weise : 

sf\T-V)dt=2(q8p-q,Sp,^  (1) 

wobei  sich  rechts  die  erstern  Grossen  auf  die  obere  die  letztern  auf  die 
untere  Integrationsgrenze  beziehen. 

1.    Hamiltons  Princip  der  stationaren  WirTcung. 

Aus  der  Fundamentalgleichung  1)  folgt  das  Princip  der  stationaren 
Wirkung,  wenn  man  die  Grenzen  des  Integrals  und  die  Coordinaten- 
werte  fiir  dieselben  als  unveranderlich  voraus  setzt.  Dann  ergibt  sich, 
wenn  man  setzt 

A  t  —  t. 

folgende  Gleichung  : 

Sn  =  0  Oder  5^=0. 


O  oder  W  haben  also  fiir  die  Bewegung  dieselbe  Bedeutung,  wie  V  fiir 
das  Gleichgewicht  in  der  Ruhe.  Die  Bedingungen,  welche  den  Grenz- 
wert  von  XI  oder  W  unter  den  geschilderten  Umstanden  angeben,  sind 
mit  den  Bewegungsgleichungen  identisch,  wesshalb  Helmholtz  diese  Gros- 


Vierte  Vorlesung.  307 

sen  als  kinetisches  Potential  bezeichnet.  Fiir  das  Gleichgewicht  in  der 
Ruhe,  bestimmen  diese  Bedingungen  einen  Grenzwert  von  F",  da  dann 
T  =0  und  V^fon  der  Zeit  unabhangig  ist.  Der  Satz,  dass  fiir  das  Gleich- 
gewicht, F'ein  Grenzwert  ist,  ist  also  ein  ganz  specieller  Fall  des  Satzes 
vom  kinetische  Potentiale  oder  des  Hamilton'schen  Princip  der  station- 
aren  Wirkung,  wie  dieser  auch  genannt  wird. 

2.    Hamiltons  Princip  der  variirenden   Wirkung. 

Wir  setzen  in  Gleichung  1)  einmal  nur  die  untere  dann  nur  die  obere, 
dann  nur  den  Wert  einer  Coordinate  fiir  die  untere,  endlich  diesen 
Wert  fiir  die  obere  Grenze  des  Integrales  als  veranderlich  voraus ;  es 
folgen  sofort  die  Hamilton'schen  partiellen  Differentialgleichungen  : 

Es  soil  nun  V  die  Zeit  nicht  enthalten,  also  die  Energie  T+  V  sich  mit 
der  Zeit  nicht  andern.  Wenn  man  dann  in  Gleichung  1)  die  Grenzen 
als  variabel  betrachtet,  so  transformirt  man  sie  nach  einigen  Zwischen- 
rechnungen  leicht  in  die  folgende  : 

2BCTdt  =  rS(r-f  V}dt  +  ^(qBp  -  q^Bp^-)  (2) 

wobei  aber  die  Sp  jetzt  unter  gleichzeitiger  Variation  der  Grenzen  fiir 
die  Zeit  und  der  Bewegung  zu  bilden  sind. 


3.    Das  alte  Princip  der  kleinsten  Wirkung. 

Setzt  man  in  Gleichung  2)  die  Coordinatenvariationen  fiir  die  Gren- 
zen von  t  gleich  Null  und  nimmt  ausserdem  an,  dass  die  Variation  der 
Bewegung  ohne  Energiezufuhr  geschieht  also  S(Th-  F)=  0  ist,  so  folgt 


also  die  alte  Form  des  Princips  der  kleinsten  Wirkung,  welches  in 
mancher  Beziehung  specieller,  in  so  fern  aber  wieder  allgemeiner  ist, 
als  das  Princip  der  stationaren  Wirkung,  als  es  die  Bewegungszeit  als 
veranderlich  betrachtet. 


308  Ludwig  Boltzmann : 

4.     Analogien  mit  dem  zweiten  Hauptsatze. 

Wir  wollen  annehmen,  class  das  letzte  Glied  der  Gleichung  2) 
verschwindet.  Es  gilt  dies  nicht  bloss,  wenn  an  den  Grenzen  fiir  die 
Zeit  hp  ■=  hpf^  =  0  ist,  sondern  audi  wenn  die  Bewegung  periodisch  ist  und 
t  —  t^  die  Dauer  dieser  Periode  ist.  Es  gilt  auch  wenn  die  Verschiebungen 
sammtlicher  materiellen  Punkte  des  Systemes  in  folge  der  Variation  der 
Bewegung  senkrecht  auf  der  augenblicklichen  Geschwindigkeitsrichtung 
derselben  steht.  Bisher  waren  die  hp  ganz  willkiirliche  Variationen. 
Wir  wollen  sie  nun  in  folgender  Weise  erzeugt  denken.  1.  Mit  dem 
Systeme,  auf  welches  sich  die  Gleicliung  2)  bezieht,  soil  ein  zweites  Sys- 
tem verbunden  sein,  welches  mit  dem  ersten  in  Wechselwirkung  steht  und 
letzteres  soil  eine  unendlich  kleine  Bewegung  machen.  2.  Ausserdem 
soil  dem  ersten  Systeme  eine  unendlich  kleine  lebendige  Kraft  S^zugefiihrt 
werden.  Die  in  der  Gleichung  vorkommende  Grosse  h  F'ist  bloss  die  Veran- 
derung  von  F'in  folge  der  Lagenanderung  der  Punkte  des  ersten  Systems. 
Sei  S'F'die  in  Folge  der  Lagenanderung  des  zweiten  Systems,  so  ist  h^V 
die  Arbeit  der  vom  ersten  auf  das  zweite  System  wirkenden  Kriifte.  Sie 
muss  mit  der  zugefiihrten  Energie  hQ  zusammen  die  gesammte  Anderung 
hE  der  Energie  des  ersten  Systems  geben.  Es  ist  also  hE=  SQ  +  B'V. 
Anderseits  ist  SjE'=  8T+  BV  +  B'  V,  da  8^ die  Anderung  der  kinetischen, 
SV-\-  8'V die  Gesammtiinderung  der  potentiellen  Energie  ist.  Aus  bei- 
den  Gleichungen  folgt  8Q  =  8  (T -{-  V).     Setzen  wir 


_  CsQdt     _  r 


Tdt 


BQ^^-^ und   T  = 

t  —  t^  I  —  Iq 

so  folgt  aus  Gleichung  2)  unter  den  gemachten  Annahmen  sofort 


T 


lognat/J  'Tdt\ 


wo  die  Analogic  mit  dem  zweiten  Hauptsatze  deutlich  zu  Tage  tritt. 
Thermodynamisches  Beispiel :  Unter  dem  ersten  Systeme  verstehen  wir 
die  Molekiile  eines  Gases,  unter  dem  zweiten  einen  das  Gas  begrenzenden 
beweglichen  Stempel,  BQ  ist  die  dem  Gase  zugefiihrte  Warme.  Mechan- 
isches  Beispiel :  Das  erste  System  ist  ein  mit  einer  punktformigen  Masse 
verbundener  Magnetpol  der  gezwungen  ist,  sich  in  einer  Ebene  zu  bewe- 
gen,  das  zweite  System  ein  kurzer  Magnet,  um  welchen  der  Magnetpol 


Vierte    Vorlesung.  309 

eine  Centralbewegung  maclit.  Nun  erfahrt  der  Magnet  eine  kleine 
Drehung  wodurch  sich  das  Wirkungsgesetz  der  Centralbewegung  andert 
und  ausserdem  der  Magnetpol  einen  kleinen  Stoss.  Das  Gesagte  soil 
gewissermassen  ein  Schema  sein,  in  welchem  die  verschiedenen  dem 
Principe  der  kleinsten  Wirkung  verwandten  Principe  zusammengestellt 
sind.  Es  zeigt  sich,  dass  die  Analogien  mit  dem  zweiten  Hauptsatze 
weder  einfach  mit  dem  Principe  der  kleinsten  Wirkung,  noch  audi  mit 
dem  Hamilton'schen  identisch  sind,  aber  sowohl  zum  einen,  wie  auch  zum 
andern  in  sehr  naher  Beziehung  stehen. 

Ich  habe  zu  Anfang  betont,  dass  die  Entwicklung  der  Wissenschaft 
nicht  immer  in  stetiger  Verfolgung  der  alten  Wege  vor  sich  geht,  son- 
dern  sehr  haufig  durch  plotzliche  Einflihrung  ganz  neuer  Methoden  und 
Ideen  gefordert  wird.  Wo  konnte  fiir  letztere  Art  der  Entwicklung  ein 
fruchtbarer  Boden  sein  als  in  Amerika,  wo  alles  neu  ist,  wo  die  Geschick- 
lichkeit  des  Geistes,  Ungewohnliches  zu  unternehmen,  die  grossten  unvor- 
hergesehenen  Schwierigkeiten  zu  besiegen  stete  tlbung  findet,  wahrend  wir 
in  Europa  wolgedrillt  in  den  Bahnen  der  alten  wissenschaftlichen  Me- 
thode  uns  zwar  mit  grosserer  Leichtigkeit  und  Sicherheit  bewegen,  als 
die  Bewohner  der  neuen  Welt,  aber  dem  Ungewohnten  und  Neuen  gegen- 
iiber  verbliifft  und  unbehiilflich  sind.  Sicher  werden  daher  nicht  bloss 
die  Amerikaner  aus  ihren  rastlosen  Bestrebungen  die  Pflege  der  reinen 
Wissenschaft  zu  fordern  den  grossten  Nutzen  ziehen,  sondern  auch  die 
Wissenschaft  wird  durch  die  Mitwirkung  der  Amerikaner  stets  mehr 
und  grossartiger  gefordert  werden.  Auch  ich  fiihle  den  hohen  bildenden 
Wert,  den  es  fiir  mich  hatte  meinen  engbegrenzten  heimatlichen  Hori- 
zont  durch  die  Bekanntschaft  mit  der  grossartigen  Natur  und  Cultur 
Amerikas  zu  erweitern,  wol  das  fruchtbringendste  Experiment,  das  ich 
je  angestellt  habe.  Ich  sage  Ihnen  daher  meinen  besten  Dank  fiir  die 
hohe  Ehre,  welche  Sie  mir  durch  die  Berufung  zu  diesen  Vortragen 
erwiesen,  und  wlinsche  nur,  dass  das  von  mir  gebotene  nicht  ganz  hinter 
der  Grosse  dieser  Auszeichnung  zuriickstehen  moge. 


COMPARATIVE   STUDY  OF   THE  SENSOET  AREAS 
OF   THE   HUMAN   CORTEX. 

By  Santiago  Ram6n  y  Cajal. 

If  order  to  respond  worthily  to  the  gracious  invitation  with  which 
Clark  University  has  honored  me,  I  ought  to  offer  you,  as  was  my  original 
intention,  a  work  of  synthesis,  a  general  summary  of  the  present  state  of 
our  knowledge  of  the  minute  anatomy  of  the  nervous  system.  Unfortu- 
nately, the  duties  of  my  professorship,  every  day  more  pressing,  have 
deprived  me  of  the  time  necessary  for  the  accomplishment  of  such  a  task, 
and  have  compelled  me  to  moderate  my  ambition,  and  to  limit  it  to 
presenting  to  you  a  modest  analytical  contribution  to  our  knowledge 
of  the  microscopical  structure  of  the  sensory  centres  of  the  human  cere- 
bral cortex,  a  subject  to  which  I  have  devoted  the  leisure  of  the  past 
months. 

This  subject  is  so  vast  and  so  difficult  that,  in  spite  of  my  efforts  and 
the  time  devoted  to  it,  I  have  been  able  to  clear  up  only  a  few  points. 
Consequently,  my  contribution  will  be,  to  my  utmost  regret,  a  very 
incomplete  one,  treating,  as  it  does,  only  the  visual  cortex  as  I  have 
made  it  out  in  man  and  some  of  the  higher  mammals.  I  shall  add, 
however,  a  few  observations  on  the  structure  of  other  sensory  regions. 

This  anatomical  study  of  the  sensory  areas  of  the  cortex,  at  the 
present  state  of  our  knowledge,  presents  points  of  special  interest,  since, 
as  you  well  know,  neurologists  who  have  interested  themselves  in  the 
histology  of  the  brain  are  divided  at  present  into  two  camps,  the  unicists 
and  the  pluralists. 

The  unicist  doctrine,  proclaimed  by  Meynert  and  reaffirmed  quite 
recently  by  Golgi  and  Kolliker,  supposes  that  all  regions  of  the  cortex 
possess  essentially  the  same  structure,  functional  diversity  being  due  to 
diversity  of  origin  of  afferent  or  sensory  nerves.  This  amounts  to  saying 
that  cerebral  specific  energy  of  nerves  is  the  necessary  effect  of  the  partic- 

311 


312  Santiacjo  Ramon  y  Cajal : 

ular  organization  of  each  sense  as  well  as  of  the  special  character  of  the 
stimuli  received  by  the  peripheral  sensory  surfaces,  skin,  retina,  organ  of 
Corti,  etc. 

The  pluralist  doctrine,  upheld  recently  by  Flechsig,  without  rejecting 
the  particular  influence  of  connections  with  different  nerves,  maintains 
that  diversities  of  function  result  also  from  the  particular  structure  of 
each  cortical  area. 

It  is  this  latter  opinion,  as  we  shall  presently  see,  that  presents  a 
closer  agreement  with  the  observed  facts.  In  fact,  my  researches  tend  to 
prove  that  the  topographical  specialization  of  the  brain  depends  not  only 
on  the  quality  of  the  stimuli  analyzed  and  gathered  up  by  the  sensory 
mechanisms,  but  also  on  the  structural  adaptations  which  the  cor- 
responding cerebral  areas  undergo;  since  it  is  very  natural  to  suppose, 
even  if  one  were  to  form  an  a  priori  judgment,  that  the  cortical  areas  con- 
nected with  the  spacial  senses  sight  and  touch,  which  form  exact  images 
of  the  exterior  world  with  fixed  relations  of  space  and  intensity,  have  by 
accommodation  to  the  stimuli  received  an  organization  different  from 
that  existing  in  cortical  areas  attached  to  the  chemical  senses  of  taste  or 
smell,  and  from  that  which  is  appropriate  to  the  chronological  sense 
hearing,  which  gives  only  relations  of  succession,  free  from  every  spacial 
quality. 

We  may  add  that  if  there  exist  in  the  human  cerebral  cortex,  as 
Flechsig  supposes,  besides  the  sensori-motor  centres,  other  regions,  asso- 
ciation centres,  characterized  by  absence  of  direct  sensory  or  motor  con- 
nections, it  seems  very  natural  also  to  associate  to  these  important 
regions  of  the  brain,  with  which  are  connected  the  highest  activities  of 
psychic  life,  a  special  organization  corresponding  to  their  supremacy  in 
the  hierarchy  of  functions. 

But  we  must  not  carry  to  an  extreme  the  structural  plurality  of  the 
brain.  In  fact,  our  researches  show  that  while  there  are  very  remarkable 
differences  of  organization  in  certain  cortical  areas,  these  points  of  differ- 
ence do  not  go  so  far  as  to  make  impossible  the  reduction  of  the  cortical 
structure  to  a  general  plan.  In  reality,  every  convolution  consists  of  two 
structural  factors:  one,  which  we  may  call  a  factor  of  a  general  order, 
since  it  is  found  over  the  whole  cortex,  is  represented  by  the  molecular 
layer  and  that  of  the  small  and  large  pyramids;  the  other,  which  we  may 
call  the  special  factor,  particularly  characteristic  of  the  sensory  areas,  is 
represented  by  fibre  plexuses  formed  by  afferent  nerve  fibres  and  by  the 


Visual  Cortex.  313 

presence  at  the  level  of  the  so-called  granular  layer  of  certain  cell  types 
of  peculiar  form. 

But,  before  proceeding  to  outline  the  general  conclusions  of  an  ana- 
tomico-physiological  order,  that  result  from  all  our  researches  taken 
together,  permit  me  to  present  very  briefly  the  facts  of  observation. 

Visual  Cortex. 

The  minute  anatomy  of  the  visual  cortex  (region  of  the  ealcarine 
fissure,  sulcus  cornu  lobulus  lingualis)  has  been  already  explored  by  sev- 
eral investigators,  among  whom  we  may  make  particular  mention  of  Mey- 
nert,  Vicq  d'Azyr,  Gennari,  Krause,  Hammarberg,  Schlapp,  KoUiker,  et  al. 
But  their  very  incomplete  researches  have  been  performed  by  such  insuffi- 
cient methods  as  staining  with  carmine,  the  Weigert-Pall  method,  or  that 
of  Nissl  with  basic  anilines  —  methods  which,  as  is  well  known,  do  not 
sufiice  at  all  to  demonstrate  the  total  morphology  of  the  elements  and  the 
organization  of  the  most  delicate  nerve  plexuses.  They  led,  however,  in 
spite  of  the  difficulties  which  stood  in  the  way  of  these  first  analytical 
attempts,  toward  a  precise  differentiation  of  the  visual  cortex  from  other 
regions  of  the  brain.  At  the  outset  two  characteristic  differences 
attracted  the  attention  of  the  first  investigators  into  the  structure  of  the 
visual  cortex :  first,  the  existence  of  a  very  thick  stratum  of  granules,  sub- 
divided into  accessory  strata  by  laminae  of  molecular  appearance;  and, 
second,  the  presence  in  the  intermediate  layers  of  the  cortex  of  a  white 
lamina  formed  of  medullated  fibres  —  which  lamina  may  be  seen  with  the 
unaided  eye.  This  lamina,  appearing  in  cross-section  as  a  white  line,  has 
been  named,  in  honor  of  the  writers  who  first  described  it,  the  line  of 
Gennari  or  Vicq  d'Azyr. 

For  the  sake  of  brevity,  we  shall  omit  a  detailed  description  and  dis- 
cussion of  the  various  layers  admitted  by  the  authorities  on  this  region  ; 
suffice  it  to  mention  in  order  the  eight  layers  described  by  Meynert  for 
the  human  cortex  :  First,  molecular  ;  the  second,  layer  of  small  pyram- 
idal cells  ;  third,  layer  of  nuclei  or  granules  ;  fourth,  layer  of  solitary 
cells  ;  fifth,  layer  of  intermediate  granules  ;  sixth,  layer  similar  to  the 
fourth,  containing  nuclei  and  scattered  cells  ;  seventh,  deep  nuclear 
layer  ;  eighth,  layer  of  fusiform  cells.  We  may  also  mention  the  ar- 
rangement of  layers  recently  described  by  Schlapp  for  the  occipital 
cortex  of  the  monkey  :  (1)  layer  of  tangential  fibres  ;  (2)  layer  of  exter- 


314 


Santiago  Ranwit  y  Cajal : 


nal  polymorphic  cells  ;  (3)  layer  of  pyram- 
idal cells  ;  (4)  layer  of  granules  ;  (5)  layer 
of  small  solitary  cells  ;  (6)  second  layer  of 
granules ;  (7)  layer  poor  in  cells  ;  (8)  layer 
of  internal  polymorphic  cells. 

The  investigations  which  I  have  made  on 
the  human  cortex  as  well  as  on  that  of  the 
dog  and  cat,  by  both  the  Nissl  and  Golgi 
methods,  have  led  me  to  distinguish  the  fol- 
lowing layers  :  — 

1.  Plexiform  layer  (called  molecular 
layer  by  authors  generally  and  cell-poor 
layer  by  Meynert). 

2.  Layer  of  small  pyramids. 

3.  Layer  of  medium-sized  pyramids. 

4.  Layer  of  large  stellate  cells. 

5.  Layer  of  small  stellate  cells  (called 
layer  of  granules  by  the  authors). 

6.  Second  plexiform  layer,  or  layer  of 
small  pyramidal  cells  with  arched  axon. 

7.  Layer  of  giant  pyramidal  cells  (soli- 
tary cells  of  Meynert). 

8.  Layer  of  medium  sized  pyramidal  cells 
with  arched  ascending  axon. 

9.  Layer  of  fusiform  and  triangular  cells 
(fusiform  cell  layer  of  Meynert). 

You  see  that  we  have  modified  current 
nomenclature  by  introducing  terms  which 
call  to  mind  cellular  morphology.  For  we 
believe  that  such  trite  expressions  as  "mo- 
lecular  layer,"    "granular   layer,"   must   be 

Fig.  1.  —  Vertical  section  of  the  visual  cortex  of  man, 
calcarine  sulcus,  stained  by  Nissl's  method  —  semischematic. 
1.  Plexiform  layer.  2.  Layer  of  small  pyramids.  3.  Layer 
of  medium-sized  pyramids.  4.  Layer  of  large  stellate  cells. 
5.  Layer  of  small  stellate  cells.  6.  Second  plexiform  layer, 
or  layer  of  small  pyramids  with  arched  axon.  7.  Layer  of 
giant  pyramids.  8.  Layer  of  medium-sized  pyramidal  cells 
with  ascending  axon.  9.  Layer  of  fusiform  and  triangular 
cells. 


Visual  Cortex.  315 

banished  once  for  all  from  scientific  language,  and  they  must  be  replaced 
by  terms  which  point  out  dominant  morphological  characters  in  the 
nerve  structures  of  each  layer  or  some  interesting  peculiarity  relative  to 
the  course  and  connections  of  the  axis  cylinder  processes.  The  number  of 
layers  could  be  easily  increased  or  diminished,  because  they  are  not  sepa- 
rated by  well-marked  boundaries,  particularly  in  Nissl's  preparations. 
Thus  the  number  of  layers  which  I  adopt  is  somewhat  arbitrary.  By 
distinguishing,  however,  nine  layers,  I  have  followed  a  criterion  of  indi- 
vidualization which  seems  to  me  the  most  convenient  and  suitable  for  my 
exposition  of  the  cortex  as  a  mechanism  composed  of  elements  at  a  cer- 
tain level  which  differ  in  special  morphological  features  from  those  of 
neighboring  levels.  Besides,  the  number,  extent,  and  size  of  cells  in  these 
layers  vary  a  little  in  the  different  median  occipital  convolutions,  as  does 
also  the  degree  of  definite  nidification,  according  as  we  study  the  convex 
or  concave  aspect  of  the  gyri.  Our  description  relates  generally  to  the 
cortex  of  the  margin  of  the  calcarine  fissure,  the  region  where  structural 
differentiation  of  the  visual  cortex  is  most  pronounced. 

Plexiform  Layer. 

The  plexiform  or  molecular  layer  is  one  of  the  oldest  cerebral  forma- 
tions in  the  phylogenetic  series.  It  presents  characters  similar  to  those 
of  the  human  cortex  in  all  vertebrates  except  the  fishes.  This  has  been 
fully  demonstrated  by  the  researches  of  comparative  histology  under- 
taken by  Oyarzun  (batrachia),  by  myself  (batrachia,  reptilia,  and  mam- 
malia), by  my  brother  (batrachia,  reptilia),  by  Eddinger  (batrachia, 
reptilia,  aves),  by  CI.  Sala  (aves).  In  the  visual  cortex  of  man,  the 
structure  of  this  layer  coincides  perfectly  with  that  which  my  own  re- 
searches, as  well  as  those  of  G.  Retzius,  have  revealed  in  the  motor 
region.  The  only  modification  which  may  be  noted,  visible  even  by 
Nissl's  method,  is  its  notable  thinness  in  the  margins  of  the  calcarine 
fissure  (except  in  the  sulci,  and  here  it  appears  somewhat  thinned). 
This  diminution  in  thickness,  noted  by  authors  generally,  depends 
probably  on  the  small  number  of  medium-sized  and  giant  pyramidal  cells 
in  the  underlying  layers,  because  it  is  well  known  that  each  pyramidal 
cell  is  represented  in  the  plexiform  layer  by  a  spray  of  dendrites.  A 
similar  opinion  has  been  expressed  by  Bevan  Lewis  in  order  to  explain 
irregularities  in  thickness  of  this  layer  in  different  regions  of  the  cortex 


316  Santiago  Ramon  y  Cajal : 

of  the  rabbit  and  guinea-pig.  The  structure  of  the  plexiform  layer  is 
very  complex.  From  my  own  researches,  confirmed  largely  by  those  of 
Retzius,  Schafer,  Kolliker,  and  Bevan  Lewis,  it  follows  that  it  consists 
of  an  interweaving  of  the  following  elements:  (a)  the  radial  branches 
of  the  small,  medium-sized,  and  giant  pyramidal  cells,  with  which  we 
must  include  in  addition  those  of  the  so-called  polymorphic  cells  ;  (6) 
layer  of  terminal  ramifications  of  the  ascending  axons  of  Martinotti ; 
(c)  layer  formed  by  the  arborizations  of  the  nerve  fibres,  terminal  or 
collateral,  which  come  from  the  white  matter  ;  (d)  layer  of  special  or 
horizontal  cells  of  the  first  layer  (Cajal's  cells,  of  Retzius)  ;  (e)  layer  of 
small  and  medium-sized  stellate  cells  with  short  axons  ;  (/)  layer  of  neu- 
roglia cells,  well  described  by  Martinotti,  Retzius,  and  Andriesen. 

a.  Terminal  Arborizations  of  the  Pyramidal  Cells  (Fig.  4). — As  my 
observations  have  shown  in  case  of  the  mammalian  cortex,  and  those  of 
Retzius  for  the  human  foetus,  the  radial  trunk  of  the  pyramidal  cells 
does  not  end,  as  Golgi  and  Martinotti  supposed,  in  a  point  entwined  by 
neuroglia  elements  in  connection  with  the  blood-vessels,  but  in  a  spray  of 
varicose  dendrites  covered  with  contact  granules,  spreading  out  some- 
times over  a  considerable  area  of  the  plexiform  layer.  In  my  first  work 
on  the  cerebral  cortex,  I  thought  that  the  only  cells  whose  terminal 
dendrites  reached  up  to  the  first  layer  were  the  medium-sized,  small, 
and  giant  pyramidal  cells ;  but  my  latest  researches  have  enabled  me 
to  discover  that  all  cells  possessing  a  radial  stem,  without  exception, 
including  even  those  of  the  deeper  layers,  are  represented  in  the  plexi- 
form layer  by  a  terminal  dendritic  arborization.  It  is  without  doubt 
an  important  structural  law  whose  physiological  import  must  be  very 
considerable.  We  may  observe  that  large  trunks  which  arise  from  the 
giant  pyramids  divide  into  a  spray  with  very  long  and  thick  branches 
having  their  distribution  in  the  deeper  level,  while  the  slender  stems 
emanating  from  the  medium  and  small  sized  pyramids  form  an  arboriza- 
tion of  numerous  slender  branches  of  limited  extension  and  distributed 
particularly  through  the  superficial  lamince  of  the  plexiform  layer.  This 
distribution,  which  is  not  absolutely  constant,  leads  us  to  surmise  that 
the  terminal  arborizations  of  each  kind  of  pyramidal  cell  come  into  contact 
witli  special  neuritic  terminal  arborizations  in  traversing  this  first  layer. 

The  trunk  and  end  brush  intended  for  the  first  layer  appear  not  only 
in  preparations  made  by  the  chromate  of  silver  method ;  for  I  have 
stained  them  perfectly  with  methylene  blue  (method  of  Ehrlich-Bethe) 


Visual  Cortex.  317 

in  case  of  young  animals,  and  also  in  adult  gyrenceplialous  mammals, 
such  as  the  dog  and  cat.  Besides,  in  good  preparations  by  Ehrlich's 
method,  particularly  when  fixation  has  been  made  a  short  time  after  the 
impregnation,  one  may  see  very  distinctly  the  contact  granules  of  the 
dendrites,  processes  which  I  was  first  to  describe  and  whose  existence 
has  been  confirmed  by  many  investigators  since.  With  methylene  blue 
they  present  the  same  appearance  as  in  Golgi  preparations,  i.e.  they  are 
slender  and  short,  stand  out  at  a  right  angle,  are  sometimes  divided,  and 
end  freely  in  a  rounded  knob.  This  proves,  accordingly,  how  groundless 
are  all  the  gratuitous  objections  which  have  been  brought  against  the 
preexistence  of  these  appendages,  as  well  as  against  their  mode  of  termi- 
nation. Among  the  entirely  arbitrary  conjectures  which  have  been  made 
as  to  the  disposition  of  these  appendages  we  include  also  W.  Hill's  opinion, 
who  considers  them  the  fibres  of  a  reticulum  that  is  incompletely  stained 
by  means  of  the  chromate  of  silver.  We  must  proclaim  emphatically 
that  at  present  there  is  no  method  of  staining  cellular  processes  that 
is  capable  of  disproving  the  agreeing  results  of  the  methods  of  Golgi, 
Ehrlich,  and  Cox.  Whoever,  having  as  a  foundation  the  revelations  of 
any  one  of  these  methods,  has  considered  it  possible  to  demonstrate  the 
existence  of  such  a  reticulum  has  only  exposed  to  view  his  own  lack  of 
experience  in  handling  these  important  means  of  analysis. 

b.  Special  or  Horizontal  Cells  of  the  Plexiform  Layer.  —  These  interest- 
ing elements,  which  I  discovered  in  the  cortices  of  the  small  mammals  (rat, 
rabbit,  guinea-pig),  have  been  successfully  investigated  by  Retzius  in 
case  of  man,  as  well  as  by  my  brother  in  batrachians  and  reptiles,  and  by 
Veratti  in  the  rabbit's  embryo.  They  present  in  the  visual  cortex,  where 
I  have  stained  them  very  often,  the  same  characters  as  in  other  regions 
of  the  brain.  As  I  have  already  described  these  elements  elsewhere,  I 
shall  give  here  only  an  outline,  to  which  I  may  add  a  few  remarks  derived 
from  my  recent  observations  upon  man  (Fig.  2). 

Following  the  example  of  Retzius,  when  we  study  the  horizontal  cells 
by  Golgi's  method  in  a  human  foetus  from  the  seventh  to  the  ninth 
month,  or  in  case  of  a  newborn  babe,  we  notice  that  they  are  distributed 
throughout  the  entire  thickness  of  the  plexiform  layer,  but  are  especially 
numerous  in  close  proximity  to  the  pia.  Their  form  is  very  variable, 
sometimes  fusiform  or  triangular,  and  again  stellate,  with  the  angles 
extending  out  into  the  long  processes.  But  the  characteristic  feature  of 
these  elements  is  due  to  the  fact  that  their  processes,  which  are  variable 


318 


Santiago  Ramon  y  Cajal: 


Visual  Cortex.  319 

in  number  and  very  large  at  their  origin,  give  rise,  after  a  few  divisions, 
to  an  extraordinary  number  of  varicose  horizontal  fibres,  extremely  long, 
from  which  spring  at  right  angles  numberless  ascending  secondary 
branches  terminating  in  rounded  knobs  near  the  cerebral  surface.  Very 
often  the  superior  surface  of  the  cell  body  also  gives  rise  to  some  of  these 
ascending  branches,  which  sometimes  have  a  considerable  thickness. 

In  what  way  do  these  tangential  fibres  terminate  ?  Is  it  possible  to 
discern  among  them  certain  processes  possessing  the  characters  of  axons  ? 

Upon  careful  examination  of  the  best  preparations  obtained  from 
cortices  of  human  embryos,  we  discover  easily  that  these  processes, 
when  they  become  very  fine,  have  all  the  appearances  peculiar  to  axons. 
There  is  no  morphological  distinction  which  would  enable  us  to  distin- 
guish the  two  classes  or  species  of  cellular  processes.  That  which  most 
strikes  one  is  the  enormous  length  of  their  horizontal  fibres  (tangential 
fibres  of  Retzius).  One  can  follow  them  for  two  or  three  tenths  of  a 
millimeter  without  being  able  to  discover  their  true  termination.  How- 
ever, in  certain  cases  it  is  possible  to  demonstrate  that  the  tangential 
fibres,  after  having  given  rise  to  a  great  number  of  vertical  twigs,  become 
thinner  and  finer,  and  finally  subdivide  into  terminal  branchlets,  which 
spread  out  under  the  pia  or  in  the  superficial  laminae  of  the  first  layer. 

On  comparing  these  cells  of  the  human  brain  with  their  homologues 
in  the  higher  mammals  (rabbit,  cat,  etc.),  we  discover  that  among  the 
latter  they  give  rise  to  a  relatively  small  number  of  tangential  branches, 
and  that  these  extend  a  much  shorter  distance.  This  is  the  reason  we 
consider  the  remarkable  profusion  and  the  extreme  length  of  the  hori- 
zontal fibres  as  one  of  the  most  characteristic  features  of  the  human 
cortex. 

Retzius  did  not  succeed  in  staining  the  horizontal  cells  in  man  except 
in  the  foetal  period.  Accordingly,  it  was  impossible  to  know  what  be- 
comes of  these  elements  in  the  adult,  and  whether,  as  Retzius  is  inclined 
to  think,  all  the  processes  that  we  find  in  the  embryonic  period  persist. 
My  recent  researches  on  the  cortex  of  infants  fifteen  months  and  even 
fifteen  and  twenty  days  61d,  in  which  I  have  been  successful  in  staining 
the  horizontal  cells,  suffice  to  furnish  a  few  data  which,  if  they  do  not 
solve  the  problem  once  for  all,  at  any  rate  place  the  question  in  a  some- 
what more  favorable  light. 

When  we  examine  the  plexiform  layer  of  a  babe  fifteen  days  old, 
we  find  considerable  changes  in  the  horizontal  cells.     First  of  all,  we 


320  Santiago  Ramon  y  Cajal: 

notice  that  they  have  become  smaller,  and  that  the  tangential  processes 
have  diminished  in  diameter  while  they  have  become  notably  lengthened. 
But  the  peculiarity  which  most  strikes  the  attention  is  the  almost  total 
disappearance  of  the  ascending  collateral  branches.  This  atrophy  begins 
in  a  progressive  thinning  of  the  processes  and  in  the  reabsorption  of  their 
terminal  varicosities  ;  then  the  whole  branch  disappears,  so  that  the  o;ily 
structures  left  are  the  horizontal  fibres,  whose  ensemble  forms  throughout 
the  thickness  of  the  plexiform  layer  a  system  of  parallel  fibres  of  enor- 
mous length.  There  are  places,  however,  where  the  ascending  branches 
persist,  but  very  much  changed  as  to  their  direction,  having  become 
oblique  instead  of  vertical,  becoming  branched  several  times,  and  termi- 
nating in  the  plexiform  layer  without  reaching  so  far  up  toward  the 
pia  as  before.  In  a  word,  most  of  the  vertical  branches  seem  to  me  to 
represent  an  embryonic  arrangement  corresponding  to  the  interstices,  for 
the  most  part  vertical,  between  the  epithelial  cells  of  the  cerebral  cortex 
of  the  foetus,  which  proves  once  more,  as  I  have  demonstrated  in  other 
nerve  centres,  that  during  the  period  of  evolution  the  neuron  is  the  locus 
of  a  double  series  of  functions:  on  the  one  side  a  vegetative  building  up 
of  the  dendrites ;  on  the  other,  reabsorptions  and  transformations  of  the 
cells  which  persist. 

Have  the  horizontal  cells  with  which  we  are  now  concerned  a  true 
functional  process  ?  In  case  this  is  so,  what  is  the  part  played  by  these 
elements  in  the  vast  system  of  nervous  relations  established  in  the  plexi- 
form layer  ? 

In  preparations  of  the  human  brain  stained  with  chromate  of  silver,  it 
must  be  confessed,  it  is  not  easy  to  solve  this  important  question,  since 
the  purely  morphological  criterion,  which  is  sufficient  to  distinguish  the 
axon  in  other  neurons,  cannot  be  applied  to  horizontal  cells,  all  the  pro- 
cesses of  which,  on  becoming  finer,  have  the  form  of  true  axons.  Thus, 
in  spite  of  Veratti's  affirmation,  we  believe  that  this  method  will  shed  no 
light  upon  the  subject,  even  when  applied  to  embryos.  In  order  to  ap- 
proximate to  any  solution  of  the  problem,  we  must  use  a  method  capable 
of  staining  nerve  prolongations  in  a  manner  to  differentiate  them  from 
dendrites.  It  was  only  after  using  Ehrlich's  methylene-blue  method  upon 
the  motor  and  visual  cortex  of  the  cat  that  I  became  convinced  that  the 
horizontal  cells  have  in  reality  a  very  long  axon,  which  is  provided  with  a 
medullary  sheath.  The  other  processes,  which  we  have  called  horizontal 
fibres,  represent  true  dendrites,  as  is  shown  by  two  peculiarities:  the  great 


Visual  Cortex.  321 

facility  with  which  they  take  methylene  blue,  and  their  pronounced  vari- 
cosity after  fixation  with  ammonium  molybdate.  We  must  repeat  that 
this  varicose  alteration,  which  is  a  striking  modification  in  the  form  of 
cellular  prolongations,  presents  itself  only  in  dendrites.  The  neurites 
maintain  perfectly,  with  methylene  blue,  their  normal  contours,  unless 
exposure  to  the  air,  necessary  to  obtain  the  selective  staining,  has  been 
too  long. 

As  to  the  axon,  it  may  be  sufficiently  well  demonstrated  in  horizontal 
sections  of  the  plexiform  layer  in  the  form  of  a  pale  blue  fibre,  except  the 
initial  portion  and  the  nodes,  which  present  a  dark  blue  staining.  This 
is  a  property  of  all  parts  of  a  fibre  not  surrounded  with  a  medullary 
sheath.  At  the  point  of  certain  constrictions  we  may  succeed  in  dis- 
covering a  few  collaterals  springing  out  at  right  angles,  provided  also 
with  myeline  sheaths.  Finally,  one  is  sometimes  so  fortunate  as  to  dis- 
cover in  an  axon  of  this  kind  true  bifurcations  situated  at  a  great  dis- 
tance from  the  cell  of  origin,  but  always  in  the  plane  of  the  plexiform 
layer.  Unfortunately,  the  methylene  blue  does  not  stain  the  terminal 
nerve  arborizations.  This  has  prevented  me  from  learning  in  just  what 
way  these  axons  terminate  and  with  what  axons  they  are  dynamically 
associated.  It  is  possible  that  certain  heavy  horizontal  fibres  come  into 
contact  with  the  horizontal  cells,  since  they  never  bend  downward 
toward  the  underlying  layers,  as  do  the  medium-sized  and  finest  medul- 
lated  fibres.  They  belong  probably  to  the  terminal  arborizations  of 
Martinotti's  ascending  axons  and,  perhaps,  also  to  the  collaterals  and 
terminals  coming  in  from  the  white  matter. 

e.  Cells  with  a  Short  Axon  (Fig.  3,  G-,JE,F}. —  A  few  years  ago,  while 
studying  the  cerebral  cortex  of  the  small  mammals,  I  discovered,  besides 
the  gigantic  horizontal  cells,  other  elements  which  I  called  polygonal  cells. 
These  are  characterized  by  their  stellate  form  and  by  their  short  axon, 
which  ramifies  and  ends  within  the  limits  of  the  plexiform  layer.  These 
cells,  whose  existence  neither  Schafer  nor  Lewis  seem  to  have  been  able  to 
confirm,  —  no  doubt  on  account  of  the  insufficiency  of  their  attempts  to 
obtain  an  impregnation  of  them,  —  are  much  more  abundant  than  might 
have  been  supposed  from  my  first  observations.  However,  I  must  acknowl- 
edge that,  they  are  not  at  all  easily  impregnated  with  chromate  of  silver 
and  that,  in  order  to  find  a  sufficient  number  for  study,  we  must  make  a 
great  many  attempts  at  staining  them.  On  the  other  hand,  Ehrlich's 
method  stains  them  very  readily  in  the  dog  and  rabbit.     In  these  animals 


322 


Santiago  Ramon  y  Cajal : 


—  and  I  think  that  it  holds  true  also  in  man  —  the  plexif orm  layer  of  the 
cerebrum  is  as  richly  supplied  with  elements  with  a  short  axon  as  the 
molecular  layer  of  the  cerebellar  cortex.  They  occur  in  all  levels  of  the 
layer  and  differ  remarkably  in  size  and  shape.  The  majority  of  them 
are  stellate  and  are  comparable  in  size  to  other  cells  with  short  axons 


Fig.  3.  —  Cells  and  neuritic  terminal  arborizations  in  the  1st  and  2d  layers ;  visual  cortex  of 
infant  20  days  old.  A  and  B,  neuritic  plexus,  extremely  fine  and  dense,  situated  in  the  layer  of 
small  pyramids;  C,  an  analogous  arborization,  but  not  so  dense;  D,  a  small  cell  whose  ascending 
axon  forms  a  similar  arborization;  i', spider-shaped  stellate  cell  of  the  1st  layer;  F,  G,  cells  with 
short  axon  branching  loosely  in  the  plexiform  layer ;  a,  axon. 

that  occur  in  the  deeper  layers  of  the  cortex.  Others  are  smaller, 
resembling  in  their  minuteness  the  granules  of  the  cerebellum.  But 
whether  large  or  small,  the  morphological  characters  of  these  elements 
are  very  similar.  Their  dendrites  are  divergent,  extremely  branched, 
and  distributed  exclusively  to  the  plexiform  layer.     Their  neurites  are 


Visual  Cortex.  323 

usually  very  short,  subdivide  in  a  most  complicated  manner  in  the  neigh- 
borhood of  the  cell,  but  never  cross  the  deep  boundary  of  the  first  layer. 

From  the  point  of  view  of  the  direction  and  length  of  their  neurites 
all  these  elements  may  be  classified  into  three  varieties  :  (1)  Stellar  cells 
with  horizontal  neurite  which  becomes  resolved  after  a  varying  distance, 
generally  very  long,  into  a  terminal  arborization  which  has  the  appear- 
ance of  being  connected  with  the  terminal  branches  of  the  remote  pyra- 
mids. (2)  Cells  of  generally  smaller  size  whose  neurite  branches  either 
laterally  or  vertically  from  the  cell  body,  but  always  at  a  moderate  dis- 
tance (Fig.  3,  (t,  jP).  (3)  Very  small  cells  (which  I  discovered  recently 
in  the  human  cerebral  cortex)  provided  with  numerous  fine,  divergent, 
and  slightly  branched  dendrites,  whose  neurite,  extremely  slender,  breaks 
up  near  its  origin  into  a  dense  arborization,  exceedingly  fine  and  compli- 
cated. We  shall  designate  these  elements  dwarf  or  spider-shaped  cells. 
They  may  be  found,  as  we  shall  see,  in  all  the  layers  of  the  cortex 
(Fig  3,  ^). 

To  sum  up  :  bearing  in  mind  the  form  of  cell  bodies  and  formation 
and  connection  of  axons,  all  the  stellate  cells  of  the  plexiform  layer, 
including  the  horizontal  or  special  cells,  seem  to  me  similar  to  the  stellate 
cells  of  the  molecular  layer  of  the  cerebellum  and  to  those  which  occur 
in  the  layers  of  the  same  name  in  the  cornu  ammonis  and  fascia  dentata. 
Their  function  is  probably  to  establish  connections  between  terminal 
arborizations  as  yet  imperfectly  made  out,  possibly  those  formed  by  the 
ascending  axons  of  Martinotti,  or  the  association  fibres  coming  up  from 
the  white  matter  with  the  terminal  branches  of  the  pyramidal  cells. 
The  function  of  the  great  horizontal  cells  would  seem  to  be  to  establish 
connections  between  elements,  that  is  to  say  between  terminal  neuritic 
arborizations  and  radial  dendrites,  separated  by  very  considerable  dis- 
tances ;  while  the  medium-sized  and  small  elements,  with  their  short 
axons,  would  perform  the  same  associative  function  at  short  or  moderate 
distances. 

d.  Martinotti' s  Ascending  Fibres. — There  is  no  lack  of  these  in  the 
visual  cortex,  although  it  has  seemed  to  me  that  they  are  not  so  numerous 
as  in  other  regions  of  the  brain.  Their  terminal  ramifications,  well  known 
from  the  researches  of  Martinotti  as  well  as  my  own,  occupy  really  the 
whole  plexiform  layer,  where  they  extend  over  wide  areas,  distributing 
themselves  preferably  into  its  deeper  levels  and  coming  in  contact  with 
cells  with  short  axons  and,  possibly,  also  with  the  large  horizontal  cells. 


324  Santiago  Ramon  y  Cajal: 

Granting  that  the  cells  of  origin  for  these  fibres  lie  in  layers  of  the  cortex 
that  contain  sensory  fibres,  we  might  suppose  that  Martinotti's  ascending 
axons  represent  intermediate  links  placed  vertically  between  these  sen- 
sory fibres  and  cells  with  short  axon  in  the  plexiform  layer.  And  as 
these  are  connected,  perhaps,  with  the  dendrites  of  the  pyramidal  cells, 
the  result  would  be  that  the  sensory  stimuli,  entering  the  cortex  in  this 
indirect  way,  would  be  compelled  to  traverse  two  intercalated  nerve 
cells  before  reaching  the  pyramids. 

e.  Neuroglia  Cells.  —  These  conform  in  the  visual  cortex  to  the  well- 
known  types  of  other  cerebral  regions.  We  find  accordingly  :  (1)  Cells 
with  long  radii,  the  marginal  cells  well  described  by  Martinotti,  which 
lie  just  under  the  pia.  They  emit  long,  smooth,  descending  processes 
radiating  across  the  plexiform  layer,  ending  at  different  levels  both  of 
this  and  of  the  layer  of  small  pyramids ;  (2)  Cells  with  short  radii. 
These  elements,  long  since  described  by  Golgi,  and  described  in  de- 
tail by  Retzius,  by  myself,  Andriesen,  Kolliker,  and  others,  are  charac- 
terized by  their  form,  very  often  stellate  or  fusiform,  by  their  location  in 
all  levels  of  the  plexiform  layer,  and  by  the  great  number  of  their  pro- 
cesses, short,  spongy,  branching,  and  bristling  with  innumerable  contact 
granules,  which  penetrate  into  the  spaces  lying  between  the  neuro-proto- 
plasmic  plexus  and  are  well  spread  over  the  interstices  of  the  elements 
which  must  not  come  into  contact.  It  is  in  virtue  of  this  intricate  rela- 
tion between  these  appendages  and  the  cell  bodies  and  dendrites,  as  well 
as  for  other  reasons  which  we  have  not  time  to  dilate  upon  here,  that  we 
attribute  to  the  neuroglia  elements  with  short  processes  an  insulating 
role.  According  to  my  view,  they  prevent  inopportune  contacts,  while 
their  processes  exercise  due  regard  to  all  points  of  cells  or  fibres  where 
contacts  exist  and  nerve  currents  pass. 

Layer  op  Small  Pyramids. 

This  layer  is  well  separated  from  the  1st,  but  blends  by  insensible 
gradations  with  the  3rd,  or  layer  of  medium-sized  pyramidal  cells  (Fig. 
4,  B). 

Examined  in  Nissl  preparations  this  layer  presents  a  great  number  of 
small  pyramids,  very  poor  in  chromatic  granules  and  separated  by  a 
plexus  of  fibrils  much  more  dense  than  in  the  case  of  cells  of  the  deeper 
layers.      We  find  also,  scattered  irregularly,  stellate  or  triangular  cells 


Visual  Cortex. 


325 


larger  than  the  pyramids.     These  are  the  giant  cells  with  short  axon,  as 
is  shown  in  good  chromate  of  silver  preparations  (Fig.  6,  2),  C).     We 
shall  now  discuss  the  cells  of  this  layer,  beginning  with  the  pyramids. 
Pyramids.  —  The  morphology  and  relations  of  these  cells  being  well 


Fig.  4.  —  Small  and  medium-sized  cells  of  the  visual  cortex  of  an  infant  20  days  old  (calcarine 
sulcus).  A,  Plexiform  layer  ;  B,  layer  of  small  pyramids  ;  C,  layer  of  medium-sized  pyramids;  a, 
descending  axon ;  b,  recurrent  collateral ;  c,  dendritic  trunk  of  giant  pyramid. 

known  since  the  researches  of  Golgi,  Retzius,  and  myself,  I  shall  limit 
my  remarks  to  a  bare  mention  of  a  few  peculiarities  of  their  disposition 
in  the  visual  cortex. 

It  \vill  be  noticed  that   these  cells  are  generally  smaller  and  more 


326  Santiago  Ramon  y  Cajal: 

numerous  in  the  visual  centres  than  in  other  cortical  areas.  Sometimes 
the  more  superficial  cells  are  arranged  in  one  or  two  regular  files  and 
separated  from  those  beneath  by  a  fine  dense  plexus  of  fibres. 

The  small  pyramids  give  rise  to  the  following  processes  :  an  axial 
dendrite,  often  bifurcated  near  its  origin,  which  runs  to  the  plexiform 
layer  and  terminates  in  a  spray  of  fine  branches,  which  often  ascend 
to  the  neighborhood  of  the  pia;  basilar  divergent  dendrites,  rather 
long  and  repeatedly  branched ;  and,  finally,  a  fine  descending  axon, 
which,  in  most  favorable  specimens,  can  be  followed  down  to  the  neigh- 
borhood of  the  white  matter.  From  the  initial  portion  of  its  course  spring 
three,  four,  or  a  larger  number  of  collateral  processes,  which  traverse, 
with  many  subdivisions,  in  a  horizontal  or  oblique  direction,  a  very  con- 
siderable extent  of  the  second  layer.  From  the  small  pyramids  lying 
close  to  the  plexiform  layer,  and  even  from  some  cells  more  deeply  situ- 
ated, the  first  two  collaterals  recurve,  ascending  sometimes,  as  Schafer 
has  discovered,  up  to  their  termination  in  the  first  layer.  However,  this 
termination  in  the  first  layer  is  much  less  frequent  than  might  be 
inferred  from  this  authority's  descriptions  and  drawings.  In  our  prepa- 
rations of  the  visual  and  motor  cortex  of  a  child  a  few  days  old  and  of  a 
cat  twenty-five  days  old,  the  great  majority  of  the  recurrent  collaterals  do 
not  cross  the  boundary  of  the  second  layer.  Here,  in  conjunction  with 
many  neurites  belonging  to  cells  with  short  axons,  they  assist  in  forming 
a  very  dense  plexus,  which  contains  in  its  meshes  the  primary  dendrites 
of  the  small  pyramids.  Generally,  —  and  this  may  be  considered  as  an 
answer  to  the  authorities  who  strive  to  convert  the  recurrent  course  of 
the  collaterals  into  an  argument  for  the  doctrine  of  the  cellulipetal  con- 
duction of  these  fibres  (v.  Lenhossek,  Schafer),  —  I  may  affirm  that  the 
vast  majority  of  the  initial  neuritic  collaterals  —  and  I. consider  such  all 
those  that  arise  within  the  gray  matter  —  always  come  into  contact  with 
some  of  the  dendrites  belonging  to  homologous  nerve  cells  situated  at  dif- 
ferent levels  of  the  same  cortical  formation.  When  the  cells  to  which 
they  correspond  lie  in  the  same  or  a  deeper  plane,  the  collaterals  intended 
for  them  take  a  horizontal,  descending,  or  oblique  course ;  but  if  the  cells 
of  the  same  category  are  situated  in  a  more  superficial  plane  than  the 
point  of  origin  of  the  collateral,  they  must  describe  a  recurrent  arc  in 
order  to  reach  their  destination. 


Visual  Cortex.  327 

Layer  of  Medium-sized  Pyramids. 

Being  a  continuation  by  insensible  gradations  of  the  small  pyramidal 
layer,  it  contains  cells  of  precisely  similar  form,  differing  from  the  cells 
of  the  second  layer  only  in  their  somewhat  greater  size,  their  longer 
radial  dendrite,  and,  ordinarily,  by  a  larger  number  of  neuritic  collaterals 
(Fig.  4,  (7).  In  the  deeper  level  of  this  layer  may  be  observed  —  very 
seldom,  however  —  large  pyramidal  cells,  but  not  so  large  as  those  situ- 
ated in  the  seventh  layer. 

Cells  with  Short  Axon  of  the  Second  and  Third  Layers.  —  These 
elements,  almost  as  numerous  as  the  pyramidal  cells  themselves,  may  be 
seen  scattered  irregularly  throughout  the  entire  thickness  of  the  two 
layers.  They  are  generally  more  numerous  near  the  limits  of  these 
layers,  that  is  to  say,  in  the  superficial  portion  of  the  second  and  in  the 
deeper  level  of  the  third  layer. 

Although  in  form  and  size  these  elements  are  very  variable,  and 
although  there  are  transitional  forms  which  make  it  often  difficult  to  dis- 
tinguish between  them  and  to  subdivide  them  into  well-pronounced  types, 
still,  by  considering  the  size  of  the  cell  body  and  the  character  of  the 
axon,  they  may  be  divided  into  the  following  five  classes  :  (a)  cells  with 
short  ascending  axon ;  (5)  cells  with  short  descending  axon ;  (e)  cells 
with  horizontal  or  oblique  axon ;  (d)  dwarf  or  spider-shaped  elements ; 
(e)  fusiform  or  bipanicled  cells,  whose  axon  breaks  up  into  a  fibrillar 
arborization. 

a.  Cells  with  Ascending  Axon  (Fig.  5,  a,  B). — As  may  be  seen  in 
Fig.  5,  these  cells  belong  to  two  principal  varieties :  (a)  Gigantic  cells, 
with  long  dendrites  (Fig.  5,  J.,  (7).  These  are  quite  numerous  in  the 
visual  cortex,  where  they  occupy  preferably  the  deep  portion  of  the  third 
layer.  Their  form  is  stellate,  sometimes  fusiform  or  triangular.  From 
their  angles  arise  several  varicose,  thick,  and  very  long  dendrites,  often 
disposed  as  two  brushes,  the  one  ascending,  the  other  descending.  The 
axon  takes  its  origin  either  from  the  cell  body  or  from  a  dendrite. 
Sometimes  it  describes  an  arc,  whose  concavity  is  toward  the  surface,  on 
its  way  outward  to  become  resolved  into  an  arborization  of  very  few 
branches.  The  characteristic  feature  of  this  arborization  is  the  enormous 
length  and  the  horizontal  or  oblique  direction  of  its  terminal  twigs. 
These  traverse  a  very  considerable  portion  of  the  second  and  third 
layers,  where  they  make  contact  with  numberless  pyramidal  cells.      It 


Fig.  5. —Large  stellate  cells  having  short  ascending  axons,  2d.  and  3d  layers,  visual 
cortex,  infant  15  days  old.  A,  elements  of  the  3d  layer  with  axons  divided  into  long  horizontal 
branches;  B,  small  cell  with  arched  axon  from  the  layer  of  small  pyramids:  C,  large  cell  with 
arched  axon;  D,  large  cell  from  the  boundary  of  the  1st  layer;  F,  cell  with  arched  ascending 
axon  branching  in  a  most  complicated  manner;  a,  a,  a,  axons. 


Visual  Cortex.  329 

may  be  added  that  these  gigantic  cells  may  be  recognized  even  in  Nissl 
preparations  by  their  stellate  form  and  considerable  size.  They  corre- 
spond, probably,  to  the  globular  cells  of  Bevan  Lewis  and  other  writers. 
(5)  Medium-sized  type  :  This  is  a  fusiform  or  stellate  cell,  whose  size 
does  not  exceed  that  of  the  small  or  medium-sized  pyramids.  It  is 
characterized  above  all  by  its  axon,  which  is  slender  and  ascending,  and 
which  terminates  in  a  complicated  arborization  with  many  varicose 
branches  and  with  relatively  small  spread  at  varying  levels  of  the  second 
and  third  layers.  As  to  the  dendrites,  they  appear  varicose  and  diverge 
in  all  directions,  but  usually  do  not  extend  to  the  first  layer  (Fig.  5,  F^ 
and  Fig.  3,  i)). 

h.  Cells  with  Descending  Axons.  — These  are  stellate,  triangular,  or  fusi- 
form, of  medium  size,  and  provided  with  many  ascending  and  descending 
dendrites.  They  occur  chiefly,  as  has  been  pointed  out  by  Schafer  for 
other  regions  of  the  cortex,  along  the  superficial  boundary  of  the  layer  of 
small  pyramids  (Fig.  5,  B,  and  6,  (7).  Their  axons  descend  through 
the  second  and  sometimes  through  the  third  layer,  giving  off  to  them 
a  few  collaterals,  and  terminate  in  a  diffuse  arborization  throughout  the 
different  levels  of  these  layers.  Very  frequently  this  axon,  after  descend- 
ing a  certain  distance,  emitting  a  few  collaterals  to  the  layer  of  small  or 
medium-sized  pyramids,  traces  an  arc  with  concavity  toward  the  surface 
and  ascends  to  terminate  in  an  arborization,  very  complicated  and  with 
exceedingly  varicose  branches,  in  the  layer  of  small  pyramids  close  to  the 
plexiform  layer  (Fig.  5,  B).  As  seen  in  Fig.  6,  which  reproduces  certain 
cells  of  short  axons  from  the  visual  cortex  of  the  cat,  these  elements  with 
descending  axons  are  very  numerous  in  other  gyrencephalous  mammals. 
We  also  find  a  variety  of  cell,  recognized  in  man,  pyriform,  uni'-polar, 
whose  single  descending  process  gives  rise  to  a  bouquet  of  varicose 
dendrites  and  an  axon  (Fig.  6,  a,  5).  The  collaterals  and  terminal 
arborizations  of  these  axons  form  in  the  cat  a  dense  plexus  throughout  the 
superficial  plane  of  the  layer  of  small  pyramids. 

The  great  number  of  cells  with  short  axons  which  occur  in  the  most 
superficial  lamina  of  the  layer  of  small  pyramids  has  induced  certain  writ- 
ers, such  as  Schafer  and  Schlapp,  to  consider  this  transitional  region  as  a 
special  layer,  which  they  call  the  layer  of  superficial  polymorphic  cells. 
We  cannot  subscribe  to  this  innovation  because,  in  spite  of  the  great 
number  of  these  cells,  this  transitional  lamina  contains  also  a  large  num- 
ber of  small  pyramids,  that  is  to  say,  cells  which,  in  addition  to  their 


130 


Santiago  Ramon  y  Cajal: 


morphological  varieties,  have  the  same  connections  as  ordinary  pyramidal 
cells.     Of  course,  if  for  the  subdivision  of  the  cortex  into  layers  we  take 


Fig.  6.  —  Cells  with  short  axons  from  the  layer  of  small  pyramids,  visual  cortex  of  cat  aged 
28  days,  a,  b,  small  pyriform  cells  with  short  descending  axons:  c,  cell  with  arched  axon;  e,  f, 
cells  with  descending  axons  distributed  to  the  medium-sized  pyramids  of  3d  layer. 

as  our  basis  of  classification  the  form  of  cell  bodies,  independently  of  other 
characters,  we  might  be  entitled  to  differentiate  between  the  first  and 
second  layer  consisting  chiefly  of  stellate  cells  ;  because  in  this  region,  as 


Visual  Coi'tex.  331 

is  well  known,  the  small  pyramids  have  a  stellate  or  triangular  form. 
But,  in  assigning  to  an  element  a  place  in  his  classification,  one  must  not 
decide  from  the  form  alone,  which  in  case  of  superficially  placed  pyramids 
is  a  function  of  their  position.  In  fact,  we  find  that  the  form  of  these 
cells  varies  according  to  their  proximity  to  the  plexiform  layer.  The 
true  characteristic  of  a  pyramidal  cell  consists  in  the  presence  of  a  long 
axon  extending  down  to  the  white  matter  and  of  a  spray  of  dendrites 
(supported  or  not  by  an  intermediate  trunk)  spreading  up  into  the  plexi- 
form layer.  Now,  in  the  light  of  such  a  criterion,  it  is  easy  to  see  that 
sufficient  reason  does  not  exist  for  making  out  of  the  most  superficial 
pyramids  a  distinct  category  of  cells  to  be  used  as  a  basis  for  the  creation 
of  a  new  cortical  layer. 

c.  Cells  with  Horizontal  or  Oblique  Axon  (Fig.  7). — These  elements, 
which  are  .angular  or  fusiform,  with  their  long  axes  more  or  less  hori- 
zontal, possess  few,  but  rather  long,  dendrites.  Their  axon  arises  gen- 
erally from  the  lateral  aspect  of  the  cell  body  or  from  a  thick  polar 
dendrite,  takes  from  the  first  a  horizontal  or  oblique  direction  and,  after 
giving  off  a  few  collaterals,  terminates,  sometimes  after  extending  to  a 
considerable  distance,  in  an  arborization  widely  spread  but  with  few 
branches.  In  certain  cells  of  this  category,  it  is  shorter  and  subdivides 
in  the  immediate  neighborhood  of  the  cell  body  (Fig.  7,  E^  C). 

d.  Divarf  or  Spider-shaped  Cells.  —  Brought  to  our  attention  by  CI. 
Sala  in  the  corpus  striatum  of  birds,  mentioned  also  by  my  brother  in 
the  cerebral  cortex  of  batrachians  and  reptiles,  these  strange  elements  are 
notably  abundant  and  of  very  pronounced  character  in  the  cerebral  cortex 
of  man  and  gyrencephalous  mammals.  They  are  found  irregularly  scat- 
tered in  all  layers  of  the  visual  area.  Their  soma  is  very  small,  not  ex- 
ceeding the  diameter  of  the  nucleus  by  more  than  five  or  six  ix.  About 
the  nucleus  is  a  thin  lamina  of  protoplasm  which  is  drawn  out  into 
a  great  number  of  dendrites,  delicately  varicose,  radiating,  slightly 
branched  and  short.  The  appearance  of  these  dendrites  is  such  that  one 
might  mistake  the  cell,  at  first  sight,  for  a  neuroglia  corpuscle  with  short 
processes.  But,  examining  them  with  a  high  power,  we  recognize  at 
once  that  their  slender  dendrites  do  not  possess  collateral  appendages 
(contact  granules),  so  characteristic  of  processes  of  neuroglia  cells.  Finally, 
attentive  examination  reveals  the  axon,  a  delicate  fibre,  which  becomes 
resolved  immediately  into  a  very  dense  varicose  arborization  of  incompar- 
able fineness.     Often  this  terminal  plexus  is  so  extremely  fine  that  it 


332 


Santiacjo  Ramon  y  Cajal: 


appears  through  an  ordinary  objective  as  a  yellowish  or  brownish  spot  in 
the  neighborhood  of  the  cell  and  resembling  somewhat  a  granular  precipi- 


FiG.  7.  —  Cells  with  short  horizontal  or  oblique  axons  situated  in  the  2d  and  3d  layers,  visual 
cortex  of  infant  a  few  days  old.  A,  B,  cells  with  axons  almost  horizontal  from  2d  layer ;  C,  D,  E, 
cells  with  short  axon  diffusely  branched ;  F,  H,  I,  pyriform  cells  of  the  1st  layer,  whose  sig- 
nificance is  still  uncertain ;  G,  small  cell  with  very  short  axon  diffusely  branching  within  the 
1st  layer. 

tate.  In  some  cases  this  arborization  is  coarser  and  can  be  seen  with  a 
Zeiss  objective  D  or  E.  At  the  level  of  the  superior  boundary  of  the 
layer  of  small  pyramids,  in  the  visual  cortex  of  the  child  and  even  of 


Visual  Cortex.  333 

other  mammals,  may  often  be  seen  a  dense  plexus  of  exceedingly  slender 
branching  fibrils.  Their  original  fibre  appears  to  come  from  the  deeper 
levels  of  the  2d  layer  (Fig.  3,  A,  B,  (7).  These  terminal  plexuses  often 
take  the  impregnation  irregularly,  which  gives  the  appearance  of  brownish 
or  coffee-colored  spots  scattered  and  sometimes  arranged  in  a  row  just 
underneath  the  plexiform  layer.  At  first  I  was  not  successful  in  tracking 
satisfactorily  the  fibres  of  origin  and,  therefore,  hesitated  as  to  stating 
the  significance  of  these  interesting  arborizations.  Very  recently,  how- 
ever, in  two  or  three  fortunate  specimens  I  have  been  able  to  demonstrate 
the  connection  between  this  plexus  and  the  fine  ascending  axons  of  certain 
small  cells  situated  in  the  deeper  level  of  the  2d  or  outer  level  of  the  8d 
layer.  I  am,  therefore,  now  inclined  to  consider  this  intermediate,  or  sub- 
plexiform,  nerve  plexus  as  consisting  of  terminal  arborizations  intended 
for  the  small  pyramids.  The  fibres  of  origin  spring  from  more  deeply  situ- 
ated spider-shaped  cells  very  hard  to  impregnate.  I  may  add  that  these 
plexuses  are  not  lacking  in  the  cat  and  dog,  although  in  these  animals 
the  fibrillse  are  not  so  numerous  nor  so  extremely  fine  as  in  the  human 
brain.  Permit  me  also  to  add  that  they  occur  in  all  regions  of  the  cor- 
tex, although  up  to  the  present  we  have  obtained  the  best  impregnation 
of  them  in  the  visual  area. 

e.  Small  Bipanicled  Cells.  —  In  the  visual  region,  as  well  as  in  other 
areas,  of  the  human  cortex  we  find  in  profusion  certain  small  cells  vertically 
elongated.  Their  axon  presents  the  very  singular  feature  of  breaking  up 
into  long  slender  brushes  of  terminal  fibrillse.  At  first,  I  thought  that 
these  singular  cells  were  forms  characteristic  of  the  acoustic  area,  for  here 
they  are  remarkably  developed  and  very  numerous.  Further  investiga- 
tion, however,  has  convinced  me  that  they  occur  in  all  parts  of  the 
cortex,  disposed  in  greatest  numbers  along  the  lower  level  of  the  2d  and 
3d  layers  (Fig.  8  and  Fig.  11,  E,  F^. 

As  stated  above,  we  are  discussing  the  small  spindle-shaped  cells 
with  poles  radially  disposed,  which  give  rise  to  groups  of  dendrites, 
slender,  unprovided  with  contact  granules,  very  finely  varicose,  and  often 
arranged  in  long  ascending  and  descending  brushes.  In  some  cases  these 
are  so  fine  that  on  superficial  examination  they  might  be  mistaken  for 
delicate  neuritic  arborizations.  But  the  most  striking  peculiarity  of 
these  cells  concerns  the  subdivisions  and  course  of  their  axons.  This  pro- 
cess is  very  delicate.  It  ascends  or  descends  a  certain  distance,  then  gen- 
erally gives  off  a  few  collaterals  at  right  angles  which  soon  subdivide  into 


334 


Santiago  Ramon  y  Cajal: 


Fig.  8.  —  Small  fusiform,  bipanicled  cells 
from  auditory  cortex  of  infant  (1st  temporal 
convolution).  A,  cell  giving  origin  to  a  de- 
scending axon  moderately  branched ;  B,  cell 
whose  axon  breaks  up  into  a  number  of  pen- 
cils of  very  long  ascending  and  descending 
fibrils;  a,  axon.  (Examined  with  Zeiss  apo- 
cliromatic  obj.  1.30.) 


ascending  or  descending  fibrillae,  and 
finally  it  breaks  up  into  brushes  of 
very  slender  filaments  which  run  radi- 
ally, extending  throughout  almost  the 
entire  thickness  of  the  cortex.  As  a 
whole  this  arborization  with  its  initial 
collaterals  forms  one  or  several  parallel 
brushes,  the  fibrils  of  which  skirt  the 
trunks  of  the  pyramids  and  adapt  them- 
selves to  the  cell  bodies,  over  which 
they  appear  to  creep,  like  the  creeping 
fibres  of  the  cerebellum  on  the  branches 
and  bodies  of  the  Purkinje  cells. 

In  the  brain  of  the  human  infant 
at  birth  these  arborizations  have  not 
attained  complete  development  and 
present  but  few  vertical  branchlets. 
It  is  not  until  twenty  or  thirty  days 
after  birth  that  we  can  observe  the 
long  and  complicated  terminal  brushes. 
In  certain  areas,  the  acoustic,  for  ex- 
ample, each  neurite  may  form  as 
many  as  five  ascending  or  descending 
brushes.  The  fibrils  of  which  they 
consist  are  so  delicate  that  in  order 
to  see  them  well  we  must  use  the 
highest  apochromatic  objectives. 

If  now  we  consider  all  the  differ- 
ent kinds  of  cells  having  short  axons, 
of  which  we  have  given  a  somewhat 
fastidious  description,  from  the  point 
of  view  of  their  connections  and  their 
probable  functions,  we  may  character- 
ize them  as  special  cells  of  association. 
The  form  of  their  cell  body  and  the  dis- 
position of  the  axon  vary  according  to 
the  number,  form,  and  position  of  the 
cells  to  which  they  must  convey  nerve 


Visual  Cortex.  335 

stimuli.  Thus  cells  with  a  horizontal  axon  must  be  intended  to  transmit 
impulses  to  elements,  probably  pyramidal  cells,  which  occur  at  the  same 
level  in  the  cortex.  Those  whose  axon  is  vertical,  ascending  or  descend- 
ing, would  naturally  transmit  impulses  to  elements  of  different  layers. 
Those  which  are  bipanicled  would  serve  to  associate  dynamically  a  great 
number  of  pyramids  in  vertical  series.  Finally,  the  small,  spider-shaped 
cells  may  have  for  their  function  association  of  groups  of  pyramids  very 
close  together.  Unfortunately  for  this  theory,  we  do  not  know  from  which 
nerve  fibres  all  these  elements  of  association  receive  their  initial  stimuli. 
Accordingly,  we  must  be  resigned  to  remain  in  ignorance  as  to  the  path  of 
the  afferent  impulses  and,  as  well,  in  regard  to  the  special  influence  which 
these  elements  must  exercise.  It  seems  very  probable,  however,  that 
their  function  consists  not  only  in  facilitating  the  spread  of  incoming 
stimuli,  but  also  in  adding  to  it  something  new,  some  specific  modifica- 
tion which  cannot  now  be  determined.  We  shall  return  to  this  point  in 
our  general  conclusions  upon  this  work.  But  we  may  see  from  the  above 
how  many  paths  nature  has  opened  up  to  render  association  of  nerve 
impulses  possible  in  every  direction  and  through  any  distance.  That 
which  proves  the  importance  of  these  association  cells  and  leads  us  to 
surmise  that  they  play  an  important  psychic  role  is  the  fact  that  they  are 
extremely  numerous  in  the  human  brain.  They  are  found  in  the  animal 
brain  as  well,  but  are  not  numerous  and  are  usually  confined  to  the 
boundary  of  the  1st  layer. 

I  conclude  here  my  exposition  of  the  prosy  topics  that  I  chose  as 
the  theme  of  this  lecture.  And  nothing  remains  except  to  thank  you  for 
the  attention  and  good  will  which  you  have  shown  me  in  spite  of  the 
extreme  dryness  of  the  subject-matter. 


LECTURE   II. 

Layer  of  the  Large  Stellate  Cells. 

My  recent  researches  in  the  visual  cortex  of  man  have  led  to  the  unex- 
pected discovery  of  certain  large  cells  of  stellate  form  possessing  an  axon 
which  descends  to  the  white  matter.  Figs.  9  and  10  represent  very 
clearly  the  most  common  forms  of  these  strange  elements.  They  are 
differentiated  immediately  from  pyramidal  cells  by  their  lack  of  a  radial 
trunk.  Generally  speaking,  the  cell  body  is  stellate,  but  there  is  no  lack 
of  semilunar,  triangular,  and  even  mitral  forms.  Their  dendrites  are 
thick  and  much  branched,  and  extend  in  all  directions,  especially  horizon- 
tally, without  ever  leaving  the  territory  of  the  4th  layer.  In  man  these 
processes  are  sparsely  provided  with  contact  granules,  while  they  are  very 
numerous  in  the  homologous  cells  of  the  mammalia  (cat  and  dog). 

As  to  the  axon,  it  is  rather  large,  arises  from  the  inferior  surface  of  the 
cell  body,  descends  through  the  4th  layer,  sometimes  tracing  here  accom- 
modation curves,  and  after  crossing  the  5th,  6th,  7th  and  8th  layer,  passes 
into  the  white  matter  and  is  there  continued  as  a  medullated  nerve  fibre. 
In  passing  through  the  4th  and  5th  layers  it  gives  off  three,  four,  or  a 
larger  number  of,  often,  very  large  collaterals  which  end  in  arborizations 
extending  over  a  considerable  area  in  these  layers.  It  is  not  uncommon 
to  see  these  collaterals  taking  a  recurrent  course  to  become  distributed  in 
planes  above  the  point  of  origin  ;  but  in  this  they  never  trespass  on  the 
boundaries  of  the  4th  and  5th  layers.  Finally,  and  this  is  a  very  frequent 
disposition  in  the  adult  cortex,  this  axon,  after  having  given  off  its  col- 
laterals, becomes  notably  finer.  Taking  into  consideration  its  diameter, 
sometimes  less  than  that  of  its  first  collateral,  we  might  be  led  to  mistake 
it  for  the  latter  rather  than  a  true  continuation  of  the  axon.  We  shall 
return  to  this  peculiarity,  which  is  presented  by  many  cells  in  the  visual 
cortex.  The  stellate  cells  present  a  similar  character  in  the  adult  human 
cortex,  and  I  reproduce  in  Fig.  10  their  principal  types  impregnated  (long 
method  of  Golgi)   in   the  case  of   a  man  thirty  years  old.     The  only 

336 


Visual  Cortex. 


337 


difference  that  we  remark  between  these  cells  in  the  adult  and  infant 
brain  is  the  greater  development  of  the  dendrites,  which  extend  long 
distances  in  horizontal  planes  in  the  adult.     The  volume  of  the  soma  also 

J 


Fig.  9.  —  Layers  4  and  5,  with  portion  of  6 ;  stellate  cells  of  the  visual  cortex,  infant  20  days 
old, calcarine  sulcus.  ^,  layer  of  large  stellate  cells;  a,  semilunar  corpuscle  ;  6,  fusiform  horizontal 
cell ;  c,  cell  with  radial  trunk ;  e,  cell  with  arched  axon ;  B,  layer  of  small  stellate  cells ;  /,  horizon- 
tal fusiform  cells ;  g,  triangular  cells  with  heavy  arching  collaterals ;  C,  layer  of  small  pyramids 
with  arched  axon ;  h,  cells  of  this  type. 

increases  with  age,  which  shows  that  growth  of  dendrites  does  not  depend 
solely  on  the  lengthening  out  of  the  initial  or  primitive  protoplasm  of  the 
cell,  but  also  on  an  actual  augmentation  of  cell  substance. 


338 


Santiago  Ramon  y  Cajal : 


Cells  with  Short  Axon.  —  As  it  happens  in  other  cortical  layers,  the 
4th  contains  a  large  number  of  cells  with  short  axon.  The  following 
three  types  may  be  distinguished  :  — 


Fig.  10.— Large  stellate  cells  of  the  adult  brain,  man  30  years  old,  neighborhood  of  calcarine 
sulcus.  A,  B,  C,  F,  stellate  cells  of  the  4th  layer ;  D,  E,  K,  medium-sized  stellate  cells  of  5th 
layer ;  G,  H,  J,  cells  with  short  axon.     (Golgi's  slow  method.) 

(a)  Cells,  stellate,  fusiform,  or  triangular,  whose  axon  ascends  to  be 
distributed  in  the  superficial  plane  of  the  4th  layer  (Fig.  11,  A,  (7,  i>). 

(5)  Cells  of  similar  form  and  position,  but  whose  axon  distributes 
itself  to  the  layer  of  medium-sized  pyramids  (Fig.  11,  B). 

(c)  Spider-shaped  cells  with  a  notably  short  axon,  as  may  be  seen 
in  Fig.  13,  E, 


Fig.  11.  — Cells  of  the  visual  cortex,  infant  15  days  old,  4th  layer.  A,  cell  sending  axon  to 
superior  portion  of  4th  layer ;  B,  cell  whose  axon  branches  to  the  3d  and  4th  layers :  C,  another  cell 
sending  branches  into  the  3d,  4th,  and  5th  layers ;  E,  F,  very  small  bipanicled  cells  from  layer  of 
medium-sized  pyramids;  a,  axon. 


340 


Santiago  Ramon  y  Cajal: 


The  cells  with  ascending  axon  are  remarkable  on  account  of  the  curi- 
ous arched  course  of  the  latter.     It  has  in  some  cases  initial  collaterals. 

The  stellate  cells  as  well  as  other  cells  with  the  short  axon  are  also 
found  in  the  cortex  of  the  cat  and  dog,  where  they  form  a  well-defined 
layer  of  their  own,  corresponding,  considering  the  character  of  its  elements, 
to  the  4th,  5th,  and  6th  in  the  visual  cortex  of  the  child.  Fig.  12.     Cells 


Fig.  12.  —  Stellate  cells  from  visual  cortex  of  a  cat  aged  28  days.  A,  layer  of  stellate  cells 
corresponding  to  the  4th  and  5th  layers  in  man ;  B,  layer  of  giant  pyramids ;  a,  h,  c,  stellate  cells 
having  long  descending  axons ;  d,  e,  medium-sized  pyramids  among  the  stellate  cells. 

with  short  ascending  axon  are  especially  numerous  and  are  characterized 
by  being  fusiform  in  shape  and  by  the  contact  granules  which  cover  the 
cell  body  and  principal  dendrites.  Besides  the  existence  of  cells  in  the 
cerebral  cortex  whose  axons  ascend,  but  do  not  make  their  way  into 
the  first  layer  as  do  those  from  Martinotti's  elements,  is  the  fact  that  I 
long  since  discovered  while  working  upon  the  motor  cortex  of  the  small 


Visual  Cortex.  341 

mammals;  this  is,  as  my  latest  observations  show,  that  these  elements  are 
very  numerous,  and  that  each  cortical  layer,  or  better,  that  each  layer  of 
a  plexiform  aspect,  contains  a  special  kind  of  this  element.  In  addition, 
as  we  shall  see  in  a  moment,  these  cells  form  a  constant  factor  in  all  the 
cortical  layers  in  which  nerve  fibres  incoming  from  the  white  matter 
make  their  terminal  arborizations. 


Fifth  Layer,  or  Layer  of  Small  Stellate  Cells. 

This  layer,  which  corresponds  to  the  greater  part  of  the  stripe  of 
Vicq  d'Azyr,  when  examined  in  Nissl  preparations  appears  to  contain  an 
enormous  number  of  small  rounded  elements  which  might  be  mistaken 
for  scattered  nuclei  not  surrounded  by  protoplasm.  But  in  these  same 
preparations  we  may  still  detect,  beside  these  corpuscles,  a  few  others, 
scattered  here  and  there,  of  stellate  or  triangular  form  and  medium  or 
large  size,  very  similar  to  the  great  stellate  cells  of  the  4th  layer. 
Golgi's  method  reveals  to  us  the  great  complexity  of  the  5th  layer,  and 
by  this  means  we  have  succeeded  in  differentiating  as  many  as  five  kinds 
of  elements.     The  following  are  the  most  common  types  :  — 

(a)  Stellate  Cells  of  Medium  Size. — These  are  exactly  similar  to  the 
stellate  cells  of  the  4th  layer.  They  are  not  numerous,  and  lie  irregu- 
larly scattered  in  all  levels  of  the  5th  layer.  Their  dendrites  diverge, 
but  run  for  the  most  part  horizontally,  and  do  not  pass  beyond  the  layer 
of  their  cells  of  origin.  Their  axons  descend  and,  after  emitting  a  few 
collaterals  to  the  5th  layer,  make  their  way  to  the  white  matter.  In 
some  cases  their  collaterals  are  given  off  lower  down,  in  the  6th  layer, 
and  then  their  course  is  recurrent,  because  they  must  make  their  terminal 
arborizations  between  homonymous  cells  (Fig.  9,  g^f). 

(6)  Cells  with  Ascending  Axon.  —  These  are  fusiform  or  triangular,  dis- 
posed with  long  axis  vertical.  Their  axon  is  similar  to  that  of  cells  of 
this  type  in  the  4th  layer.  That  is  to  say,  after  ascending  a  certain  dis- 
tance it  forms  a  terminal  arborization  of  arching  branches  distributed 
among  the  elements  of  the  overlying  layer.  From  its  initial  portion 
spring  a  few  collaterals  which  are  distributed  to  the  5th  layer  (Fig.  13, 
A,  B,  C). 

((?)  Ovoid  or  Stellate  Corpuscles  (jproperly  designated.,  Grranules').  — 
These  rarely  exceed  in  diameter  more  than  ten  or  twelve  fi.  They  are 
the   most  numerous  element  of   the   5th  layer.      Their  soma  is  ovoid, 


342 


Santiago  Ramon  y  Cajal : 


spheroidal,  and  even  polygonal  in  form  and  gives  rise  to  three,  four,  or 
more  fine,  smooth  dendrites,  which  terminate,  after  a  short,  wavy  course, 
within  the  limits  of  the  5th  layer.     Their  axons  are  very  delicate  and 


Fig.  13. —  Cells  in  the  5th  layer  with  ascending  axon,  visual  cortex  of  infant  aged  15  days. 
A,  B,  cells  whose  axons  subdivide  in  the  layer  of  large  stellate  cells  ;  C,  cells  whose  axons  give  rise 
to  branches  destined  for  the  layer  of  medium-sized  pyramids;  D,  cell  with  arched  axon,  the  initial 
portion  of  which  gives  rise  to  branches  for  the  4th,  5th,  and  even  6th  layers ;  E,  very  small  cells, 
arachniform,  with  delicate  ascending  axons;  a,  axon. 


Visual  Cortex. 


343 


take  a  great  variety  of  directions,  —  ascending,  descending,  or  horizontal, 
and  finally  end  in  an  extended  arborization  of  few  branchlets  dis- 
tributed exclusively  to  the  very  midst  of  the  5th  layer  (Fig.  14). 

(^d)   Dwarf  or  Spider-shaped  Corpuscles.  —  Of  these  there  is  no  lack  in 


Fig.  14.  —  Small  cells  in  the  layer  of  small  stellate  cells,  possessing  short  diffuse  axons  (infant 
20  days),  a,  cells  with  delicate  ascending  axon;  b,  c,  cells  with  descending  axon;  d,  larger  cell 
whose  axon  forms  its  terminal  arborization  in  the  4th  layer ;  a,  axon. 


344 


Santiago  Ramon  y  Cajal : 


this  layer,  whose  nerve  plexus  they  help  to  bewilder.     Their  very  tiny, 
often  ascending,  axon  resolves  itself  very  soon  into  an  extremely  dense, 


Fig.  15.  —  Cells  with  short  axons  of  the  layer  of  stellate  cells  from  the  visual  cortex  of  a  cat 
aged  28  days,  a,  large  cell  whose  descending  axon  subdivides  in  the  deeper  level  of  the  4th  layer 
(4th  and  5th  of  man) ;  6,  arachniform  cell  whose  axon  forms  a  fine  and  very  dense  plexus ;  d,  fusi- 
form cell  whose  axon  is  resolved  into  vertical  branches. 

fine  arborization  close  to  the  cell.  In  the  dense  masses  of  these  arbo- 
rizations we  notice  spaces,  which  probably  correspond  to  groups  of 
granules. 


Visual  Cortex. 


345 


The  cells  with  short  axons  are  very  abundant  in  the  visual  cortex  of 
the  cat,  as  may  be  observed  by  examining  Figs.  15  and  16.  Among  them 
the  more  abundant  types  are :  a,  fusiform  cells  whose  ascending  axon  is 
distributed  to  the  superior  levels  of  the  layer  in  question  (4th  and  5th  in 
man)  (Fig.  16,  i));  b,  large  stellate  cells  with  descending  axon  forming 
their  terminal  arborizations  in  the  deeper  levels  of  this  layer  (Fig.  15,  a) ; 


Fig.  16.  —  Elements  from  the  layer  of  stellate  cells  of  the  visual  cortex  of  a  cat  aged  about  one 
month.  A,  B,  C,  small  pyramids  with  axons  arched  and  ascending;  D,  large  fusiform  cells  with 
ascending  axons ;  E,  arachniform  cells  with  short  axon  ;  a,  axon. 

c,  stellate-arachniform  cells  whose  axon  forms  a  most  complicated  arboriza- 
tion (Figs.  15,  5,  and  16,  J57);  d,  bipanicled  cells  larger  than  corresponding 
cells  in  the  human  brain  (Fig.  15,  c?). 

Nerve  Plexus  of  the  -^th  and  bth  layers  of  the  Cortex.  One  of  the  chief 
characteristics  of  these  layers  consists  in  the  very  dense  plexus  of  medul? 
lated  fibres  extending  among  their  nerve  cells.  This  is  formed  by  two 
kinds  of  fibres  :  (1)  Exogenous  fibres,  that  is  to  say  those  coming  from  the 
white  matter,  probably  continuations  of  the  cerebro-optic  tract.     (2)    En- 


346  Santiago  Ramon  y  Cajal: 

dogenous  fibres,  formed  by  the  terminal  arborizations  of  the  axons  which 
come  from  cells  of  the  4th  and  5th  or  the  underlying  layers. 

Exogenous  Fibres.  —  I  have  already  stated  that  Gennari's  or  Vicq 
d'Azyr's  stripe  corresponds  chiefly  to  the  5th  layer,  but  also  includes  part 
of  the  4th.  However,  the  true  composition  of  this  stripe  cannot  be  seen 
in  Weigert-Pal  preparations,  because  the  hematoxylin  stains  only  the  large 
or  medium-sized  fibres  which  possess  a  myeline  sheath.  Now  these  fibres, 
as  we  shall  presently  see,  represent  but  a  very  small  portion  of  the  com- 
ponents of  Gennari's  stripes.  Very  fortunately  Golgi's  method,  applied 
to  the  brain  of  an  infant  at  birth  or  but  a  few  days  old,  affords  us  a  very 
clear  view  of  the  medullated  and  unmedullated  fibres  which  make  up  this 
plexus.  This  method  accordingly  furnishes  us  a  means  of  analyzing  its 
origin  and  manner  of  termination.  Permit  me  to  state  at  the  outset  that 
the  principal  contingent  of  exogenous  fibres  is  represented  by  a  consid° 
erable  number  of  fibres  from  the  white  matter,  which  I  shall  henceforth 
call,  in  virtue  of  their  physiological  significance,  optic  fibres. 

The  optic  fibres  are  easily  distinguished  from  the  axons  of  the  pyra- 
mids by  their  direction,  which  is  oblique  (in  some  cases  they  are  tortuous 
or  even  stair-shaped),  by  their  large  calibre,  often  exceeding  that  of  axons 
of  the  giant  pyramids ;  finally  by  the  fact  that,  instead  of  going  to  a  cell 
as  its  axon,  they  repeatedly  divide  dichotomously,  each  branch  resolving 
itself  into  a  perfectly  free  terminal  arborization  spreading  almost  horizon- 
tally through  the  extent  of  the  4th  and  5th  layers.  Fig.  17  reproduces  the 
appearance  of  the  optic  plexus  in  a  preparation  in  which  it  was  impreg- 
nated almost  alone.  I  call  your  attention  to  the  fact  that  these  optic  fibres 
send  off  no  collaterals,  or  very  few,  in  passing  through  the  deeper  layers 
(9th,  8th,  7th,  6th),  but  immediately  on  reaching  the  5th  layer  their  final 
ramification  begins.  This  occui-s  in  many  ways.  Some  fibres  divide  at 
different  levels  of  the  5th  layer  into  two  equal  or  unequal  branches  which 
run  horizontally  to  great  distances,  becoming  resolved  into  a  great  number 
of  collaterals  which  ramify  throughout  the  entire  thickness  of  the  layer. 
Other  fibres  may  be  seen  which,  after  giving  off  a  few  long  collaterals 
during  their  ascent  through  the  5th  layer,  reach  up  to  the  extreme  limit 
of  the  5th  layer  and  here  become  horizontal.  There  is  no  lack  of  fibres 
which  ascend  directly  up  to  the  limit  of  the  layer  of  medium-sized  pyra- 
mids and  there  describe  arcs,  and  even  very  long  wavy  courses,  and  end 
by  descending,  dividing  as  they  descend,  through  the  4th  and  5th  layers. 
Finally,  from  the  arching  portion  of  some  of  these  latter  fibres  fine  collat- 


Visual  Cortex. 


347 


erals  may  be  seen  to  spring  on  their  way  to  the  layer  of  medium-sized 
pyramids,  where  they  disappear  after  a  few  divisions.  To  sum  up,  the 
optic  fibres  terminate  al- 
most exclusively  within 
the  4th  and  5th  layers. 
In  only  two  instances 
have  I  discovered  col- 
laterals of  optic  fibres 
which  appeared  to  form 
their  terminal  arboriza- 
tions within  the  1st 
layer. 

This  plexus  of  optic 
fibres  is  one  of  the  rich- 
est and  densest  to  be 
found  in  the  gray  mat- 
ter of  the  brain.  If  it 
is  completely  impreg- 
nated, which  frequently 
occurs  in  an  infant  brain 
fifteen  or  twenty  days 
old,  it  appears  as  a  be- 
wildering meshwork  of 
wavy  fibres,  besprinkled 
with  vacant  spaces  cor- 
responding to  the  cell 
bodies  of  these  layers 
(Fig.  18,  ^). 

I  may  add  that  the 
appearance  of  this 
plexus  diffres  a  little 
in  the  two  layers  (Fig. 
18) 


Fig.  17.  — Heavy  fibres  coming  from  the  white  substance 
and  subdividing  in  Gennari's  stripe ;  visual  cortex  of  infant  aged 
three  days.  A,  white  substance;  B,  layer  of  small  stellar  cells; 
C,  arched  fibres  of  4th  layer  ;  D,  border  of  layer  of  medium- 
sized  pyramids ;  a,  trunks  of  the  incoming  fibres  ;  b,  collaterals 
In    the    4th   layer    for  the  deeper  layers;  c,  ascending  collaterals  destined  for  the 


^,  ,  ,     more  superficial  layers. 

its  fibres  are  larger  and 

often  disposed  in  arches  or  horizontal  bars,  its  arborizations  are  loose 
and  separated  by  ample  spaces  in  conformity  to  the  size  of  the  great 
stellate  cells;  while  in  the  5th  layer  it  consists  of  fine  varicose  fibrils 
arranged  in  an  extremely  dense  latticework  with  small  spaces,  corre- 


348  Santiayo  Ramon  y  Cajal : 

sponding   to   the    small   size   of    the   medium-sized   stellate    cells  (Fig. 

18,  By 

111  the  preceding  brief  description  I  have  called  the  large  exogenous 
fibres  optic  fibres.  But  what  reasons  have  we  to  suppose  that  these 
fibres  actually  come  in  from  the  primary  optic  centres'?  We  must 
acknowledge,  at  the  outset,  that  the  proof  of  their  optical  origin  is  not 
perfect ;  but  there  is  no  lack  of  facts  which  favor  such  a  view.  Some  of 
these  facts  are  the  following  :  — 

(a)  In  the  minute  brains,  as,  for  example,  that  of  a  newborn  mouse, 
we  can  follow  these  fibres  in  some  cases  to  the  radiation  of  Gratiolet. 

(h)  The  fibres  which  are  on  their  way  to  Gennari's  plexus  are  very 
large,  larger  than  the  axons  of  the  giant  pyramids  or  those  of  cells  of 
intercortical  association. 

(c)  In  the  motor  cortex  we  have  found  that  large  fibres  distributed  in 
a  similar  way  actually  come  in  from  the  corona  radiata. 

(cZ)  In  the  visual  cortex  of  a  man  who  became  blind  I  have  discov- 
ered, by  using  Nissl's  method,  a  perceptible  atrophy  of  the  stellate  cells 
of  the  4th  and  5th  layers.  A  similar  case  has  been  recently  reported  by 
Cramer ;  and  this  fact  would  seem  to  point  to  an  intimate  union  between 
these  elements  and  the  act  of  visual  perception,  a  union  whose  material 
bond  is  probably  represented  by  the  exogenous  fibres  of  Gennari's  plexus. 

(e)  Granted  that  the  visual  cortex  must  receive  a  great  number  of 
fibres  from  the  radiation  of  Gratiolet,  it  is  natural  to  refer  to  this  source 
the  fibres  which  form  Gennari's  plexus  ;  since  this  is  the  distinctive 
plexus  of  this  region  of  the  brain. 

From  the  probable  fact  that  the  plexus  of  Gennari's  stripe  is  the 
terminus  of  the  optic  fibres,  we  may  draw  the  important  conclusion  that 
the  cells  of  the  4th  and  5th  layers  represent  histologically  the  principal 
substratum  for  visual  sensation ;  because  up  to  this  point  in  the  cortex 
sensory  impulses  heap  up  on  the  centripetal  side,  and  here  begin  to 
become  centrifugal. 

Another  conclusion  not  less  interesting  follows  from  it :  for  an  ensem- 
ble of  anatomico-physiological  facts  seem  to  show  that  the  region  of  the 
calcarine  fissure  is  not  the  locus  of  visual  memories,  but  only  that  of  sen- 
sations of  luminosity,  and  that  the  residues  of  the  latter  must  go  (in 
order  to  become  transformed  into  latent  images)  to  other  nerve  centres. 
We  are  naturally  led  to  consider  the  long  axon  of  the  4th  and  5th  layers 
as  the  principal,  if  not  the  only,  path  joining  these  two  kinds  of  centres. 


Visual  Cortex. 


349 


Fia.  18.  —  Nerve  plexus  of  the  4th  and  5th  layers  from  the  visual  cortex  of  an  infant  aged  20 
days.  A,  B,  C,  respectively,  layers  4th,  5th,  and  6th ;  a,  trunks  of  optic  fibres ;  b,  axons  of  cells  of 
the  6th  layer ;  c,  ascending  axons  of  cells  in  the  8th  layer ;  d,  bundle  of  axons  descending  from  the 
medium-sized  pyramids  ;  e,  transverse  arches  of  the  optic  fibres  giving  rise  to  ascending  collaterals. 


350  Santiago  Ramon  y  Cajal : 

These  fibres  would  function,  accordingly,  in  carrying  the  copy,  or  the 
sensory  residue,  received  in  Gennari's  plexus,  to  appropriate  association 
areas  of  the  brain.  Their  psychic  role  is  thus  a  very  important  one,  and 
we  should  suppose  that  their  interruption  would  produce  psychic  blind- 
ness as  certainly  as  the  destruction  of  the  occipital  lobe  itself. 

The  plexus  of  Gennari  is  well  developed  in  other  mammals,  but  the 
terminal  arborizations  are  never  as  complicated  as  in  man  (Fig.  19). 
Further  than  this  I  have  not  been  able  to  demonstrate  any  definite  differ- 
ences in  arrangement  at  various  levels  of  the  layer  of  stellate  cells.  How- 
ever, it  has  seemed  to  me  that  the  terminal  branches,  which  are  very 
varicose,  tend  to  be  especially  dense  in  the  superficial  planes  of  this  layer. 

Endogenous  Fibres.  —  In  addition  to  the  large  nerve  fibres  entering 
from  the  white  matter,  Gennari's  plexus  contains  either  terminal  or 
collateral  ramifications  of  fibres  which  arise  in  the  cells  proper  of  the 
visual  cortex.     Such  are  :  — 

(1)  The  very  numerous  branches  from  the  small  cells  with  short  axon 
of  the  5th  layer. 

(2)  The  terminal  neuritic  arborizations  of  cells  with  ascending  axon 
lying  in  the  6th,  7th,  and  8th  layers. 

(3)  Arborizations  of  collateral  branches  supplied  to  the  4th  and  5th 
layers  by  the  long  descending  axons  of  the  stellate  cells. 

(4)  Terminal  arborizations  from  the  fusiform  or  triangular  cells  of  the 
4th  and  5th  layers  which  have  ascending  axons,  etc. 

The  plexus  formed  by  all  the  above  fibrils  is  usually  finer  than  that 
of  the  optical  fibres.  In  order  to  make  out  to  the  best  advantage  its 
extreme  complication  throughout  its  whole  extent,  we  must  study  it  in 
the  cortex  of  an  infant  from  fifteen  to  twenty-five  days  old,  a  period  at 
which  the  terminal  arborizations  of  the  visual  cells  are  completely  devel- 
oped. It  has  seemed  to  me  that  the  endogenous  arborizations  are  more 
numerous  in  the  4th  than  in  the  5th  layer.  We  may  notice  also  that 
they  show  a  tendency  to  form  true  nests  surroundmg  the  stellate  cells  of 
these  two  median  layers. 

Sixth  Layer. 

Plexif  orm  and  poor  in  cells  in  Nissl  preparations,  it  contains  a  large 
number  of  small  pyramidal  or  ovoid  elements  with  long  axis  vertical  and 
provided,  as  may  be  seen  in  good  Golgi  specimens,  with  a  radial  trunk 
extending   up   to   the   first  layer.     They  have   also  a   few  short  basilar 


Visual  Cortex. 


351 


YiG  19. —  Optic  fibres  from  visual  cortex  of  cat  5  days  old.  A,  bifurcation  of  fibres  a  short 
distance  from  the  white  matter ;  B,  nerve  plexus  in  layer  of  stellate  cells  (4th  and  5th  layers 
in  man). 


352  Santiago  Ramon  y  Cajal: 

dendrites,  descending  or  oblique  and  little  branched.  But  the  most  dis- 
tinctive character  of  these  small  elements  consists  in  the  course  of  their 
axons.  These  descend  a  short  distance,  then  curve  upward  and  ascend 
through  the  6th,  5th,  and  4th  layers,  to  which  they  give  a  few  collaterals, 
and  end  in  a  manner  which  I  have  not  been  able  to  discover.  In  some 
cases  these  axons  have  branched  close  to  their  origin  and,  instead  of  one, 
describe  two  arcs  continued  by  ascending  fibres.  Other  axons,  more- 
over, make  even  a  greater  number  of  loops.  From  the  convex  aspect  of 
these  curves,  as  well  as  from  the  ascending  portion  of  the  axons,  within 
the  6th  layer  spring  numerous  collaterals  which  branch  throughout  the 
entire  thickness  of  the  layer.  Some  descend  still  further  and  subdivide 
in  the  plexus  of  the  7th  layer,  that  is  to  say,  at  the  level  of  the  giant 
pyramids  (Fig.  20,  B). 

Besides  these  small  cells,  which  are  certainly  the  most  abundant,  we 
find  two  other  cellular  types  :  (a)  Cells  of  stellate  form  and  medium 
size.  They  possess  radiating  dendrites  which  do  not  usually  pass  beyond 
the  6th  layer.  Their  axons  ascend  and  form  an  arborization  throughout 
the  extent  of  the  6th,  5th,  and  4th  layers.  (5)  Ordinary  pyramidal  cells, 
very  scarce,  of  medium  or  large  size.  They  have  precisely  the  same 
characters  as  the  pyramids  of  the  7th  layer. 

Seventh  Layer  or  Layer  of  Giant  Pyramids. 

Solitary  Cells  of  Meynert.  —  This  layer  contains  one  or  two  irregular 
and  discontinuous  files  of  giant  pyramids,  which  appear,  here  and  there, 
lost  as  it  were  in  a  dense  and  extended  plexus.  To  this  plexus  the  layer 
owes  its  finely  granular  appearance,  which  may  be  seen  even  in  prepara- 
tions stained  by  Nissl's  method  (Fig.  20,  (7,  and  Fig.  22,  B^. 

The  cells  in  question,  like  other  pyramidal  cells,  possess  a  very  large 
radial  trunk  which  ends  in  a  flattened  spray  of  horizontal  branches  in  the 
lower  levels  of  the  plexiform  layer.  The  cells  are  also  provided  with 
a  few  many-branched  basilar  dendrites  which  distribute  themselves 
throughout  the  layer  and,  finally,  with  a  great  number  of  horizontal 
dendrites  forming  a  plexus  which  would  seem  to  provide  connections 
between  these  cells  through  long  distances.  This  is  such  a  characteristic 
feature  that  by  its  presence  alone  we  are  able  to  distinguish  the  visual 
from  all  other  cortical  areas.  The  axon  of  the  giant  pyramids  is  very 
large,  extends  almost  vertically  through  the  8th  and  9th  layers,  and  is 


Visual  Cortex. 


353 


continued  as  a  fibre  of  the  white  matter.  Collaterals  spring  from  its 
initial  portion  which  ramify  in  the  7th  and  even  the  superficial  levels  of 
the  8th  layer. 

In  addition  to  the  giant  pyramids,  which  in  some  cases  are  not  at  all 


Fig.  20.  — Cells  of  the  6th  and  7th  layers  from  the  human  visual  cortex,  infant  15  days  old. 
A,  5th  layer ;  B,  6th  layer ;  C,  7th  layer ;  a,  giant  pyramid;  b,  medium-sized  pyramid  with  descend- 
ing axon;  c,  small  pyramid  with  arched  ascending  axon;  d,  pyramid  whose  axon  presents  two 
arches ;  e,  pyramid  whose  axon  gives  rise  to  several  arched  fibres ;  h,f,  g,  stellate  cells  with  ascend- 
ing axons  ramified  in  the  5th  and  6th  layers ;  i,  J,  K,  pyramids  whose  axons  arch  and  subdivide 
in  the  7th  and  8th  layers. 

numerous,  the  7th  layer  contains  :  (a)  a  number  of  medium-sized  pyra- 
mids possessing  the  same  characters  ;  (6)  several  small  elements  exactly 
similar  to  those  of  the  6th  layer,  the  cells  with  the  complicated  forked  and 
arched  axons  distributed  in  the  manner  above  described  (Fig.  20,  K,  i,  J) ; 
(<?)  in  addition  may  be  found  medium-sized  stellate  cells  situated  in  the 
2a 


354 


Santiago  Ramon  y  Cajal 


7th  and  8th  layers  (Fig.  21,  A,  B).  The  very  remarkable  feature  of  the 
latter  cells  consists  in  their  terminal  arborizations.  Their  neurites  take 
at  first  an  ascending  or  oblique  course,  divide  into  two,  and  then  give 
rise  to  a  large  number  of  oblique  or  horizontal  branches  which  occupy 


Fig.  21.  —  Special  cells  of  the  7th  layer,  visual  cortex  of  infaut.  A,  B,  stellate  cells  whose  axons 
form  terminal  arborizations  in  the  layer  of  giant  pyramids;  C,  cell  with  long  ascending  axon  dis- 
tributed to  the  4;th  and  5th  layers;  D,  giant  pyramid  of  7th  layer ;  c,b,  axons  of  small  pyramids  of 
6th  layer. 

a  good  part  of  the  7th  layer.  In  the  brain  at  birth  their  terminals 
present  no  special  peculiarities ;  but  in  one  twenty  days  old  I  have  found 
that  a  number  of  these  arborizations  surround  the  giant  pyramids,  form- 
ing terminal  nests.  Only  their  arrangement  is  not  so  definite  here  as  in 
the  motor  region,  where  we  find  it  wonderfully  developed.  (Compare 
with  description  below.) 


Visual  Cortex.  355 


Eighth  Layer. 


Examined  in  Nissl  preparations  this  layer  presents  a  mass  of  medium- 
sized  pyramids  and  a  remarkably  dense  formation  of  granules.  This  is 
the  reason  IMeynert  and  other  writers  have  called  this  the  layer  of  deep 
granules  or  inferior  granular  layer. 

Golgi's  method  reveals  in  this  formation  elongated  cells  of  pyramidal 
form.  They  have  the  radial  trunk  continued,  up  to  the  plexiform  layer 
and  also  descending  basilar  dendrites  which  become  subdivided  and  end 
within  the  8th  layer.  Among  these  there  is  no  lack  of  fusiform  or  tri- 
angular cells,  but  they  always  present  the  long  radial  trunk  which  we 
find  over  the  whole  cortex  (Fig.  22,  (7). 

In  general  form,  it  will  be  observed  that  these  cells  resemble  true 
pyramids.    However,  the  peculiar  behavior  of  their  axons  establishes  a  very 
clear  distinction  between  them.     As  may  be  seen  in  the  figure  (22,  i), 
this  axon  at  first  descends,  then  describes  an  arc,  ascends  into  the  7th, 
6th,  and  5th  layers,  and  finally  ends  in  a  horizontal  arborization  chiefly 
distributed  to  the  layer  of  stellate  cells,  but  a  few  of  its  branches  go  to 
the  5th  layer.     From  the  loop  of  the  axon,  and  in  the  course  of  its  ascent, 
spring  several  collaterals,  which  ramify  in  different  planes  of  the  8th  layer. 
In  a  few  of  these  cells  we  may  observe  that,  at  the  bend  of  the  axon,  a 
slender  branch,  similar  to  a  collateral,  is  given  off,  which  crosses  the  8th 
and  9th  layers  and  enters  the  white  matter  as  a  meduUated  fibre  (Fig. 
22,  g).     The  great  majority  of  these  collaterals,  however,  terminate  com- 
pletely within  the  8th  and  9th  layers.     At  any  rate,  we  must  distinguish, 
considering  the  morphology  of  their  axons,  two  kinds  of  cells  :    (a)  cells 
with  arched  axon  none  of  whose  collaterals  extend  to  the  white  matter ; 
(J)  cells  whose  neurite  divides,  at  the  arch,  into  a  fine  descending  branch, 
which  becomes  a  medullated  fibre  of  the  white  matter,  and  into  a  larger 
ascending  branch  with  its  terminal  arborization  in  the  4th  or  5th  layers. 
This  arched  arrangement  of  the  axon  in  cells  of  the  8th  layer  appears 
very  strange.     It  occurs  not  only  in  the  infant  brain,  but  in  the  visual  cor- 
tex of  the  adult  as  well.     It  seems,  at  first  sight,  to  violate  all  laws  that 
govern  the  length  and  direction  of  the  axons  in  other  sections  of  the 
nervous  system.     And,  what  seems  still  more  remarkable,  all  these  whim- 
sical windings  seem  to  subserve   solely  the  purpose  of   shortening  the 
stretch  between  the  cell  body  and  the  first  collaterals  given  off  by  the 
arch.     This  same  phenomenon  occurs  in  many  other  nerve  cells.     Were 


Fig.  22.  —  Seventh  and  8th  layers,  visual  cortex  of  cat,  aged  20  days.  A,  deeper  portion  of 
layer  of  stellate  cells ;  B,  layer  of  giant  pyramids ;  C,  layer  of  medium-sized  pyramids  with 
arched  axon;  a,  b,  pyramids;  c.  d,  small  pyramids  with  axons  distributed  to  7th  layer;  g,  tri- 
angular cell,  whose  axon  gives  rise  to  a  large  ascending  collateral ;  i,  another  whose  axou  forms 
an  arch  and  ascends ;  1,  pyramid  with  axon  descending  to  white  matter ;  j,  element  from  the  deep- 
est levels  of  the  layer  of  medium-sized  pyramids  (corresponding  to  layer  of  fusiform  cells  in  man) 
which  gives  origin  to  a  large  axon  that  ascends  possibly  to  the  1st  layer. 


Visual  Cortex.  357 

it  not  for  a  deviation  from  our  present  theme,  I  might  adduce  very  con- 
vincing instances  of  this  tendency  of  the  axon  to  take  the  direction  most 
favorable  for  the  nerve  impulses  which  arise  in  the  cell  to  very  quickly 
reach  the  elements  connected  with  their  initial  collaterals. 

Permit  me  also  to  add  that  the  8th  layer  contains  giant  stellate 
cells  with  ascending  axon  (Martinotti's  cells),  which  runs  to  the  plexi- 
form  layer  (Fig.  22,  j),  and  also  a  similar  but  smaller  cell,  whose  axon 
gives  rise  to  an  arborization  between  the  neighboring  cells. 

Ninth  Layer. 

Coinciding  closely  with  the  so-called  polymorphic  layer  of  other 
authors,  this  layer  contains  elongated  elements,  fusiform,  triangular,  or 
ovoid,  possessing  a  radial  dendrite,  extending  up  to  the  plexiform  layer, 
and  also  one  or  several  basal  dendrites,  which  take  a  descending  or 
oblique  direction.  Finally,  these  cells  have  an  axon  which  descends  in  a 
straight  line  to  the  white  matter;  where,  after  giving  off  several  col- 
laterals, it  continues  as  a  meduUated  fibre.  There  are  also  in  the  9th 
layer  a  few  fusiform  cells  with  short  radial  dendrites  and  ascending 
axon  and  a  number  of  stellate  cells  with  short  axon  of  the  so-called 
Golgi  type. 

In  addition,  the  arrangement  of  the  cells  of  the  9th  layer  varies 
greatly  in  different  parts  of  a  convolution.  In  the  convex  portion  they 
are  very  numerous,  fusiform,  and  slender,  elongated  and  perfectly  radial ; 
while  opposite  the  sulcus  they  have  a  quite  different  form,  are  stouter, 
more  variable,  and  frequently  lie  with  long  axis  parallel  to  the  white 
matter,  i.e.  perpendicular  to  their  ordinary  direction.  Their  peripheral 
processes  perform  the  most  whimsical  contortions  in  order  to  become 
radial  and  reach  the  plexiform  layer.  Their  axon  appears  frequently 
horizontal,  describing  a  very  open  curve  on  its  way  to  the  white  matter. 
All  these  forms  and  many  others  represent  adaptations  of  the  cells  to 
the  foldings  of  the  cortex  and  to  its  varying  thickness  in  different  parts 
of  a  convolution. 

I  will  not  impose  further  upon  your  indulgent  attention  with  these 
tiresome  enumerations  of  layers  and  forms  of  cells,  in  the  mazes  of  which 
nature  herself  seems  to  have  intended  to  lose  the  investigator  and  put 
his  patience  to  the  test.     And  I  will  close  this  tedious  lecture  with  a 


358  Santiago  Ramon  y  Cajal: 

succinct  exposition  of  the  anatomico-physiological  inductions  that  seem 
to  follow  from  my  observations  on  the  minute  structure  of  the  visual 
cortex  of  man  and  the  mammalia. 

1.  The  visual  cortex  of  man  and  gyrencephalous  mammals  possesses  a 
special  structure  very  different  from  that  of  any  other  cortical  area. 

2.  The  visual  region  is  characterized,  above  all,  by  fewness  of  giant 
pyramids  and  by  presenting,  at  the  level  of  the  granular  layer  of  other 
cortical  areas,  three  distinct  layers  of  cells  of  special  form,  to  wit :  the 
layer  of  large  stellate  cells,  the  layer  of  small  stellate  cells,  and  the  layer 
of  pyramids  with  arched  ascending  axon. 

3.  Gennari's  or  Vicq  d'Azyr's  stripe  contains  principally  terminal 
arborizations  of  certain  very  large  fibres,  originating  probably  in  the 
primary  optic  centres  (external  geniculate  body,  pulvinar,  anterior  cor- 
pora quadrigemina). 

4.  Since  these  optic  fibres  are  distributed  chiefly  to  the  stellate  cells 
of  the  4th  and  5th  layers,  it  seems  natural  to  consider  these  elements 
the  substratum  of  visual  sensation. 

5.  The  innumerable  cells  with  short  axons  in  the  4th  and  5th  layers 
represent,  probably,  the  intermediate  links  between  the  optic  fibres  on 
the  one  side  and  the  stellate  cells  of  the  4th  and  5th  layers  and  the  pyram- 
idal cells  on  the  other. 

6.  As  these  intermediate  cells  are  often  very  small  and  have  short 
axons,  it  may  be  that,  besides  their  function  of  diffusing  the  incoming 
impulses  through  the  cortex,  they  play  also  the  special  role  of  augment- 
ing the  visual  impulses  by  fresh  discharges  of  nerve  force,  in  order  that 
they  may  reach,  in  sufficient  strength,  the  cortical  regions  in  which  the 
function  of  commemorative  recording  of  optical  images  occurs.  The 
pathways  for  conveyance  of  visual  residues  from  the  median  occipital 
region  to  the  association  centres  in  the  parietal  cortex  are  possibly  repre- 
sented by  axons  of  the  stellate  cells  of  the  4th  and  5tli  layers. 

7.  Granting  that  the  giant  pyramids  of  other  cortical  regions  give 
rise  to  motor  fibres,  it  would  follow  that  in  the  7th  layer  they  possess 
the  same  function.  These  cells,  whose  dendritic  trunks  come  into  con- 
tact with  the  optical  plexus,  4th  and  5th  layers,  serve  probably  to  mediate 
the  reflexes  of  the  eyeball  and  head  (conjugate  movements  of  the  eyes) 
occasioned  by  elective  stimulation  of  the  visual  cortex,  a  theory  which 
would  seem  to  be  supported  by  the  physiological  experiments  of  Schafer, 
Danillo,  Munk,  and  others. 


Visual  Cortex.  359 

8.  Granting  that  each  giant  pyramid  comes  into  contact  in  the  4th 
and  5th  layers,  as  well  as  in  the  first  layer,  with  fibres  that  are  proba- 
bly associative,  we  may  suppose  that  motor  discharges  of  these  cells  can 
be  effected  by  two  kinds  of  impulses :  by  ordinary  optical  stimulation 
and  by  stimuli  of  a  volitional  order,  possibly  coming  from  the  association 
centres  and  reaching,  finally,  the  plexiform  layer. 

My  own  researches  do  not  furnish  grounds  for  further  conclusions. 
Many  points  still  remain  to  be  cleared  up ;  but  their  complete  eluci- 
dation will  be  the  fruit  of  researches  more  detailed  and  exact  than  those 
I  have  been  able  to  undertake. 


LECTURE   III. 
The  Sensori-Motor  Cortex. 

After  the  study  that  we  have  just  made  of  the  visual  cortex,  we  can 
be  more  concise  in  our  examination  of  the  motor  area.  In  all  cortical 
regions  we  notice  general  structural  characters  and  special  features  which 
constitute  the  physiognomy  proper  of  each  cerebral  area.  Naturally, 
the  latter  will  be  of  more  interest  to  us,  and  they  will  form  the  subject  of 
the  present  lecture. 

I  shall  not  stop  here  to  give  any  history  of  researches  undertaken 
upon  the  minute  anatomy  of  the  psycho-motor  areas.  A  bibliography  of 
the  subject  would  be  very  long,  tedious,  and  altogether  superfluous,  since 
it  has  already  been  provided  in  the  recent  studies  of  Retzius,  Hammar- 
berg,  and  KoUiker.  It  will  suffice  to  name,  among  those  to  whom  we  are 
most  indebted  for  a  knowledge  of  the  structure  of  the  motor  cortex,  Mey- 
nert,  Baillarger,  Kolliker,  Krause,  Betz,  Lewis,  Golgi,  Martinotti,  Retzius, 
Flechsig,  Kaes,  Hammarberg,  Nissl,  etc.  All  these  writers  have  selected 
the  psycho-motor  cortex  for  special  study  ;  and  it  is  safe  to  assert  that 
all  our  knowledge  of  the  minute  structure  of  the  entire  cortex  has  taken 
its  character  from  this  region,  which  some  writers  have  denominated 
"  typical."  They  have  done  this  because  it  was  thought  at  the  time  when 
the  fundamental  works  of  Meynert  and  Golgi  appeared  that  in  histologi- 
cal structure  the  whole  cortex  corresponded  to  a  uniform  design,  present- 
ing only  unimportant  variations  in  different  regions. 

Neither  have  I  time  to  enumerate  the  layers  which  have  been  described 
for  this  cerebral  region.  Their  number  has  varied  under  the  pen  of  each 
writer  with  the  animal  and  the  method  he  has  happened  to  employ.  Thus 
Meynert,  who  made  his  observations  on  man,  distinguished  five  layers ; 
Stieda,  Henle,  Boll,  and  Schwalbe  limited  their  number  to  four ;  while 
writers  like  Krause  admitted  as  many  as  seven.  I  myself,  at  the  time  of 
my  investigations  upon  the  small  mammals,  recognized  four,  naming  them  : 
(1)  molecular  layer ;   (2)  layer  of  small  and   medium-sized  pyramids ; 

360 


Sensori-Motor  Cortex. 


361 


(3)  layer  of  large  pyramids ;  (4)  layer  of 
polymorphic  cells.  This  number,  derived 
particularly  from  study  of  the  small  mam- 
mals, is  not  valid  in  the  more  complicated 
human  cortex.  To  the  four  classical  layers 
of  smooth-brained  mammals  we  must  add 
one  at  least,  the  so-called  granular  layer  of 
Meynert  and  other  writers.  This  layer, 
situated  in  its  very  midst,  divides  the  layer 
of  giant  pyramids  into  two,  which  we  may 
call  respectively  the  external,  or  superficial, 
and  the  internal,  or  deep,  layers  of  giant 
pyramids. 

To  sum  up,  the  following  are  the  layers 
which  it  is  possible  to  recognize  by  Nissl's 
method  in  the  human  motor  cortex  (ascend- 
ing frontal  and  ascending  parietal  convolu- 
tions). To  conform  to  our  scheme  in  the 
visual  cortex,  we  have  altered  the  terminol- 
ogy for  this  region  also. 

1.  Plexiform  layer  (layer  poor  in  cells 
of  Meynert,  molecular  layer  of  some 
writers). 

2.  Layer  of  small  and  medium-sized 
pyramids. 

3.  External  layer  of  giant  pyramids. 

4.  Layer  of  small  stellate  cells  (gran- 
ular layer  of  the  authors). 

5.  Internal,  or  deep,  layer  of  giant 
pyramids. 

6.  Layer  of  polymorphic  cells  (fusiform 
and  medium-sized  pyramids  of  certain 
writers). 

Fig.  23.  —  Section  of  adult  human  motor  cortex, 
stained  by  Nissl's  method  (semischematic) .  1,  plexiform 
layer  ;  2,  layer  of  small  pyramids ;  3,  layer  of  medium- 
sized  pyramids  ;  4,  external  layer  of  giant  pyramids  ; 
5,  layer  of  small  stellate  cells ;  6,  internal  layer  of  giant 
pyramids ;  7,  layer  of  polymorphic  cells  or  deep  pyramidal 
layer  of  medium-sized  cells;  8,  layer  of  fusiform  cells. 


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362  Santiago  Ramon  y  Cajal : 

These  layers  correspond  particularly  to  the  concave  portions  of  the 
motor  convolutions.  Over  the  convexities  the  gray  matter  is  thickened 
especially  at  the  level  of  the  polymorphic  layer,  which  here  appears 
divided  into  two  sub-layers  :  an  external,  very  rich  in  pyramidal  and 
triangular  cells  (Fig.  23,  7) ;  the  other,  internal,  presenting,  besides 
the  heavy  bundles  of  white  fibres,  fusiform  cells  disposed  in  parallel 
series  (Fig.  23,  8). 

1.  Plexiform  Layer.  —  This  is  similar  in  structure  in  the  motor  and 
visual  areas.  It  contains,  therefore  :  (1)  dendritic  arborizations  of  the 
pyramidal  and  polymorphic  cells,  that  is  to  say,  of  all  the  cells  of  deeper 
layers  (2,  3,  4,  5,  6)  except  stellate  cells  of  the  4th  layer  and  the  cells 
with  short  axons  scattered  through  the  entire  cortex  ;  (2)  terminal  arbori- 
zations of  the  ascending  axons  of  Martinotti ;  (3)  the  ramifications  of 
the  recurrent  collaterals  which  come  up  from  the  axons  of  certain  small 
and  medium-sized  pyramids  ;  (4)  the  fibres,  terminal  and  collateral,  which 
arise  from  the  white  matter ;  (5)  stellate  cells  of  variable  size  with 
short  axon  which  ramifies  within  the  1st  layer ;  (6)  the  special,  or  hori- 
zontal, cells  with  long  tangential  dendrites  ;  (7)  finally,  neuroglia  cells  of 
the  two  well-known  types,  with  long  radiating  processes  close  underneath 
the  pia  (Martinotti,  Retzius,  Andriesen,  Bevan  Lewis,  et  al.},  and  type 
with  short  processes,  located  at  all  levels  of  the  plexiform  layer  (Golgi, 
Cajal,  Retzius,  Martinotti). 

We  shall  not  enter  upon  their  descriptive  details,  since  all  the  struc- 
tures present  the  same  characters  here  as  in  the  visual  cortex.  We  shall 
merely  add  that  in  the  motor  cortex  the  plexiform  layer  is  notably  thick. 
It  also  contains  a  greater  number  of  horizontal  cells  and  terminations  of 
the  trunks  of  pyramidal  cells  (Fig.  25,  A,  B,  C).  Its  greater  thickness 
arises  probably,  as  Lewis  remarks,  from  the  extraordinary  number  of 
pyramidal  cells  in  the  underlying  layers. 

2.  Layer  of  Small  and  Medium-sized  Pyramids  (Fig.  24,  2  and  3).  — 
We  shall  not  stop  upon  these,  because  they  are  so  well  known.  Permit 
me  merely  to  call  to  mind  the  fact  that  their  radial  trunk,  often  forked 
near  its  origin,  makes  its  arborization  in  the  plexiform  layer ;  while  from 
the  base  springs  a  fine  neurite  which,  in  case  of  the  small  mammals,  we 
can  trace  into  the  white  matter.  In  the  child's  cortex  this  is  made  diffi- 
cult by  the  distance,  but  I  have  been  fortunate  on  two  occasions  in  fol- 
lowing this  axon  into  the  medullary  substance,  where  it  was  continued 
as  a  medullated  fibre.     The  neuritic  collaterals  are  also  very  numerous 


SensorirMotor  Cortex. 


363 


and  a  number  of  them  may  be 
seen  to  recur  and  make  their  arbo- 
rizations in  the  superficial  lamina 
of  the  plexiform  layer. 

Cells  with  Short  Axons. — These 
are  numerous,  although  it  does 
not  seem  to  me  that  they  are  so 
extremely  abundant  as  in  the 
visual  region.  In  Fig.  25  I  have 
reproduced  some  of  these  ele- 
ments which  habitually  occur  in 
my  preparations.  We  remark 
especially :  a,  a  large  stellate  type, 
whose  ascending  axon  subdivides 
into  horizontal  or  oblique  branches 
covering  a  great  extent  of  the 
layer  of  small  and  medium-sized 
pyramids  (Fig.  25,  K};  b,  a  second 
type  of  similar  form  but  whose 
axon  forms  its  terminal  arboriza- 
tion very  close  to  the  cell  (Fig. 
25,  ^);  c,  still  another  form  with 
horizontal  axon  the  superficial 
branches  of  which  penetrate  into 
the  plexiform  layer  (Fig.  25,  i)) ; 
d,  arachniform  cells  with  axons 
subdivided  into  dense  plexuses 
(Fig.  25,  F,  Gr)  ;  e,  fusiform,  bi- 
panicled  cells,  which  have  been 
sufficiently  described. 


Fig.  24.  —  Ensemble  of  layers  of  motor 
cortex  of  infant  aged  one  and  a  half  months ; 
Golgi's  method  (semischematic) .  Layers  are 
numbered  as  follows:  1,  plexiform;  2  and  3, 
small  and  medium-sized  pyramids ;  4,  super- 
ficial giant  pyramids  ;  5,  granular  or  small 
stellate  cells ;  6,  deep  giant  pyramids ;  7,  poly- 
morphic cells,  or  deep  medium-sized  pyramids. 
(In  this  figure  I  have  not  represented  the 
deepest  portion  of  the  7th  layer.) 


364 


Santiago  Ramon  y  Cajal : 


Having  studied  all  these  types  and  many  others  in  the  visual  cortex, 
it  is  unnecessary  here  to  enter  upon  a  more  detailed  description.     One 


Fig.  25.  —  Cells  with  short  axons  of  the  plexiform  and  small  and  medium-sized  pyramidal  cell 
layers  from  motor  cortex  of  iufant  aged  one  month  and  a  few  days.  A,  B,  C,  horizontal  cells  of  the 
plexiform  layer;  D,  cell  with  horizontal  axon;  E,  large  cell  with  very  short  diffusely  subdivided 
axon ;  F,  G,  spider-shaped  cells  whose  delicate  axons  form  a  dense  plexus  {G)  up  to  the  plexiform 
layer ;  H,  J,  bipanicled  cells. 

thing  concerning  the  bipanicled  cells  I  may  add,  viz.,  that  in  the  motor 
cortex  there  appear  to  be  two  kinds :  one,  small  cells  provided  with 
slender  axon  disposed  in  very  delicate  vertical  pencils  (Fig.  25,  H^ ;  the 


Sensor i- Motor  Cortex.  365 

other  consisting  of  relatively  large  cells  having  very  long  and  thick  den- 
drites and  with  an  ascending  or  descending  axon  giving  rise  to  terminal 
arborizations  of  extreme  complexity,  producing  nests  or  terminal  bas- 
kets about  the  bodies  of  the  small  and  medium-sized  pyramidal  cells 
(Fig.  25,  J").  Possibly  this  type,  which  I  take  to  be  a  variety  of  the 
common  bipanicled  cell,  is  present  over  the  whole  cortex ;  but  as  yet  I 
have  succeeded  in  finding  it  only  in  the  motor  convolutions  of  the  infant 
at  over  one  month  of  age. 

3.  Superficial  Layer  of  Giant  Pyramids.  —  Being  a  continuation  by 
imperceptible  gradations  of  the  above,  this  layer  contains  the  well-known 
large  pyramids  of  the  writers.  In  addition  to  the  observations  of  Betz, 
Lewis,  Golgi,  and  myself,  however,  I  must  add  a  single  detail  to  their 
classical  description.  The  radial  process  varies  greatly  as  to  the  extent 
of  surface  it  covers  in  the  plexiform  layer.  When  its  dendrites  must 
cover  a  large  surface,  the  trunk  forks  near  the  cell,  and  the  two  trunks, 
deviating  at  an  acute  angle,  ascend  to  give  rise  to  two  or  more  terminal 
sprays,  in  some  cases  at  considerable  distances  apart.  This  amounts  to 
saying  that  certain  medium-sized  and  large  pyramids  stand  related  to  a 
large  number  of  nerve  fibres  in  the  1st  layer,  while  other  cells  of  the  same 
size  have  more  limited  connections  (Fig.  24). 

In  gyrencephalous  mammals,  dog  and  cat,  the  superficial  large  pyra- 
mids are  smaller  than  in  the  infant.  They  might  be  considered  as  a  sub- 
ordinate element  in  the  layer  of  medium-sized  pyramids.  Most  frequently 
the  only  giant  pyramids  in  the  cat  occur  below  the  granular  layer,  —  a 
layer  which,  I  may  add,  is  very  slightly  developed  in  this  animal,  being 
often  blended  with  the  layer  of  medium-sized  pyramids. 

The  number  of  superficial,  medium-sized,  and  giant  pyramids  is  very 
large  in  the  motor  area  both  in  animals  and  man ;  and  this  is  one  of  its 
characteristic  features.  However,  the  regions  designated  by  Flechsig  as 
association  centres  possess  also  a  notable  number  of  large  pyramids. 
From  this  feature  alone  it  would  be  quite  difficult  to  distinguish  the 
frontal  and  parietal  from  the  motor  convolutions. 

The  axon  of  the  large  and  medium-sized  pyramids  descends,  as  is  well 
known,  to  the  white  matter  and  is  continued  as  one  or  two  nerve  fibres. 
I  must  call  special  attention  to  the  fact  that,  as  shown  by  my  own 
researches,  this  fibre  may  fork  usually  into  a  fine  branch  which  goes, 
probably,  to  the  corpus  callosum  and  a  larger  branch  to  the  corpus  stria- 
tum.    This  may  be  easily  observed  in  the  brain  of  a  newborn  mouse  or 


366  Santiago  Ramon  y  Cajal : 

in  one  a  few  days  old.  It  may  also  be  seen  that  the  fibre  entering  the 
corona  radiata  passes  beyond  the  corpus  striatum,  giving  off  to  it  a  few 
collaterals.  It  is  thus  well  established  that  the  axon  of  the  large  pyra- 
mids is  true  projection  fibre  which  takes  part  in  forming  the  pyramidal 
tract.  But  we  must  be  on  our  guard  about  accepting  the  view  of  certain 
writers,  —  v.  Monakow,  for  example,  —  who  ascribe  tliis  role,  participa- 
tion in  the  motor  tract,  exclusively  to  the  giant  pyramids,  because  I  have 
demonstrated  beyond  all  doubt,  in  the  motor  region  of  the  mouse  and 
rabbit,  that  a  number  of  the  axons  of  medium-sized  pyramids  and  many 
from  polymorphic  cells  also  penetrate  the  corpus  striatum.  I  therefore 
consider  as  wholly  arbitrary  all  the  opinions  which  tend  to  attribute  an 
exclusive  function  to  elements  in  each  distinct  cortical  layer.  In  the  cor- 
tical layers,  as  well  as  in  the  ventral  horn  of  the  spinal  cord,  there  occur 
together  elements  with  axons  of  very  diverse  character  and  connections. 
The  motor  cell  takes  its  place  beside  the  associational  cell  along  with  the 
element  whose  axon  or  collateral  goes  to  the  corpus  callosum.  There 
are,  accordingly,  in  the  cortex  no  "  sensory  layers  "  nor  "  motor  layers  "  ; 
because,  as  we  shall  see  in  a  moment,  the  great  majority  of  the  cells 
are  related,  either  by  their  cell  bodies  or  by  their  radial  trunks,  to  the 
plexus  of  sensory  fibres.  We  find  thus  reproduced  the  arrangement  of 
the  spinal  cord,  where  all  the  cells,  or  almost  all,  come  into  contact  with 
sensory  fibres  of  the  first  or  second  order,  and  all  represent  links  in  the 
chain  of  reflex  connections. 

4.  Layer  of  Small  Stellate  Cells  {G-ranular  Layer  of  the  Authors). — 
Stained  by  Nissl's  method  the  layer  of  small  stellate  cells  appears  as  a 
great  number  of  nuclei  surrounded  with  little  protoplasm  which  contains 
a  few  fine  granules  of  chromatin  (Figs.  23,  5,  and  2-i,  5).  Most  of  these 
elements,  the  granules  proper,  are  very  small  and  globular  or  stellate  in 
form.  Others,  I  have  observed,  are  comparable  to  small  pyramids,  being 
of  triangular  form  and  having  a  fine  radial  trunk.  Nor  is  there  any 
lack  of  stellate  or  fusiform  cells  of  considerable  size,  which  call  to  mind 
those  of  the  visual  cortex.  All  these  elements  appear  to  be  mingled. 
However,  in  certain  places  I  thought  I  could  discover  that  the  small 
globular  cells  are  situated  chiefly  in  the  external  plane  of  the  layer,  while 
the  minute  pyramids  were  more  numerous  in  the  deeper  levels,  but  there 
are  exceptions  to  this. 

But  Nissl's  method  does  not  enable  us  to  study  the  fine  processes  of 
these  elements.     To  this  end  we  must  have  recourse  to  the  chromate 


Sensori^Motor  Cortex,  367 

of  silver  method,  and  by  its  application  —  especially  in  case  of  an  infant 
fifteen  to  thirty  days  old,  a  time  at  which  the  reaction  is  easily  obtained  — 
I  have  been  able  to  demonstrate  the  extreme  complexity  of  the  granular 
layer.  Good  preparations  show  that  it  consists  of  elements  with  very 
diverse  characters,  which  in  spite  of  their  minor  differences  may  be 
classed  into  two  groups  :  (1)  cells  with  long  axons  which  extend  down 
to  the  white  matter;  (2)  cells  with  short  axons  which  end  within  the 
granular  layer  or  in  layers  above  it. 

Cells  with  Long  Axons.  —  These  may  be  classed  into  two  varieties, 
small  pyramidal  cells  and  medium-sized  stellate  cells. 

(a)  The  small  pyramid  is  specially  numerous  in  the  deep  level  of  the 
4th  layer  (Fig.  26,  J.,  B~).  It  has  been  figured  by  various  writers, 
notably  by  KoUiker,  although  even  he  does  not  give  us  any  information 
on  the  character  of  its  axon.  The  cells  are  ovoid-pyramidal  in  form. 
They  possess  a  radial  trunk  which  extends  up  to  the  plexiform  layer, 
where  it  ends  in  a  few  very  slender  varicose  twigs  without  contact 
granules.  It  also  has  a  few  tiny  descending  or  oblique  dendrites  which 
divide  repeatedly.  Finally,  I  have  very  often  traced  its  axon  to  the  white 
matter,  in  which  it  is  continued  as  a  slender  medullated  fibre.  From 
its  initial  portion  arise  two,  three,  or  four  collaterals,  some  of  which  curve 
upward  to  distribute  themselves  through  the  4th  layer.  In  some  cases 
the  diameter  of  these  collaterals  is  so  large,  compared  with  that  of  the 
axon,  that  they  might  be  considered  the  real  axons. 

(6)  Stellate  Cells.  Very  hard  to  stain,  and  possibly  quite  scarce.  Their 
dendrites  arise  from  the  angles  of  the  cell  body  and  run  in  all  directions, 
but  are  distributed  exclusively  to  the  4th  layer  (Fig.  26,  i>).  Their  axons 
spring  from  the  inferior  surface,  descend  almost  in  a  straight  line,  and, 
after  giving  oif  a  few  large  collaterals,  very  frequently  arched  and  re- 
current, are  lost  in  the  white  matter.  These  interesting  cells,  exactly 
similar  to  the  stellate  cells  of  the  visual  cortex,  are  also  found  in  the 
motor  cortex  of  gyrencephalous  mammals,  although,  to  judge  from  my 
own  preparations,  only  in  small  numbers.  Their  presence  would  seem 
to  indicate  distinctively  sensory  regions  of  the  brain. 

Elements  with  Short  Axons.  —  These  are  also  very  numerous  in  the 
infant  brain,  representing,  perhaps,  the  chief  morphological  factor  of  the 
4th  layer.  Several  varieties  have  been  distinguished,  of  which  the  most 
common  are  the  following  :  — 

(a)  Stellate  or    Fusiform    Cells  of   Medium   Size.     Their   dendrites 


368 


Santiago  Ramon  y  Cajal: 


diverge  in  all  directions,  but  chiefly  above  and  below,  and  end  in  the 
midst  of  the  4th  layer.  Their  axon  springs  from  the  superior  surface, 
ascends  for  a  variable  distance,  and  at  varying  levels  of  the  layer  of  stel- 


Fio.  26.  —  Cells  with  long  axons  from  4th  layer  of  motor  cortex  of  infant  aged  one  month. 
A,  B,  C,  small  pyramidal  cells;  D,  large  stellate  cell;  E,  medium-sized  pyramid;  a,  axon;  6,  c, 
large  descending  collaterals. 

late  cells  forms  an  arborization  of  horizontal  or  oblique  branches  of  con- 
siderable length  and  distributed  exclusively  to  the  4th  layer.  Very 
often  the  axon  branches  in  the  form  of  a  T  before  proceeding  to  its  ter- 
minal arborization,  and  from  its  initial  part  arise  collaterals  whose  course 


Sensor ir Motor  Cortex. 


369 


and  terminations  resemble  those  of  the  terminal  branches.     These  cells, 

we  may  add,  correspond  in  all  points  to  the  cells  with  ascending  axons 

described  for  the  4th  and  5th  layers  of  the  visual  cortex  (Fig.  27,  A^  (7,  D). 

(6)  Fusiform,  Triangular,  or  Stellate  Cells.       These   are   somewhat 


Fig.  27.  —  Cells  with  short  axons  from  4th  layer  of  motor  cortex  of  infant.  A,B,C,  cells,  stel- 
late or  fusiform,  with  ascending  axon  divided  into  long  horizontal  branches ;  E,  arachniform  cell ; 
F,  cell  with  axon  distributed  to  layer  of  medium-sized  pyramids. 

larger  than  the  preceding.  Their  axon  ascends  to  the  plexiform  layer, 
in  which  it  subdivides  and  terminates.  In  its  ascent  it  supplies  a  few 
collaterals  to  the  4th  and  3d  layers.  These  elements,  as  we  see,  corre- 
spond to  the  so-called  cells  of  Martinotti.  In  a  few  cells  of  this  class 
the  axon  possibly  does  not  reach  the  first  layer,  becoming  lost  in  the 
layers  below  (Fig.  27,  A). 

2  B 


370  Santiago  Ramon  y  Cajal: 

(e)  Small  Stellate  or  Spider-shaped  Cells.  These  possess  fine  and 
richly  subdivided  dendrites  and  also  a  neurite,  which  forms  a  very  rich 
arborization  close  to  the  cell  (Fig.  27,  -^). 

(c^)  Bipanicled  Cells.  These  have  the  characteristics  already  de- 
scribed in  our  study  of  the  visual  cortex. 

(g)  Finally,  in  the  cat  and  dog  I  have  found  a  few  stellate  cells 
with  very  numerous  dendrites,  whose  descending  neurite  forms  a  very 
dense  and  complicated  arborization,  for  the  most  part  in  the  4th  layer, 
but  in  some  cases  extending  down  to  the  deep  layer  of  giant  pyramids. 
Possibly  these  cells  are  homologous  to  the  spider-shaped  cells  in  man, 
which  they  resemble  in  the  extraordinary  richness  of  the  plexus  formed 
by  the  axon.  It  would  then  be  necessary  to  suppose,  however,  that  in 
the  cat  and  dog  these  cells  are  much  larger  than  in  man. 

In  order  to  complete  my  description,  permit  me  to  add  that  there  is 
no  lack  of  ordinary  pyramidal  cells,  in  some  cases  large,  scattered  irregu- 
larly in  the  4th  layer  (Fig.  26,  ^).  In  mammals  like  the  cat  and  dog, 
and  to  a  much  greater  degree  in  the  rabbit,  the  profusion  of  pyramidal 
cells  obscures  our  picture  of  the  granular  layer. 

Sensory  Nerve  Plexus  of  the  4th  Layer.  —  One  of  the  most  significant 
facts  which  I  have  discovered  in  the  motor  cortex  is  a  plexus  of  very 
large  fibres  whose  numerous  subdivisions  occupy  the  4th  layer  and 
extend  even  into  the  2d  and  3d.  They  probably  enter  the  cortex  from 
the  corona  radiata.  As  early  as  in  my  first  work  I  called  attention  to 
these  fibres  as  being  different  in  diameter,  direction,  and  origin  from 
axons  of  pyramidal  cells,  but  at  that  time  I  had  not  succeeded  in  deter- 
mining the  region  to  which  they  are  peculiar  or  the  precise  place  of  their 
termination  in  the  cortex.  My  recent  researches  upon  the  brain  of  man 
and  also  small  mammals  enable  me  to  add  a  few  details  to  my  description 
of  some  years  ago  (Fig.  28). 

First  of  all,  I  have  been  able  to  determine  exactly  their  origin  and 
position  in  the  brain.  These  are  both  easy  to  observe  in  the  brain  of  a 
rabbit  at  birth  and  still  better  in  that  of  a  mouse  a  few  days  old.  In  the 
mouse  it  may  be  seen  especially  well  that  certain  large  fibres  (called  by 
KoUiker,  who  has  confirmed  their  existence,  fibres  of  Cajal)  proceed  from 
the  corpus  striatum,  enter  the  white  matter,  and  often  extend  horizon- 
tally in  it  for  great  distances.  In  their  course  they  throw  off  long  col- 
laterals, which  penetrate  into  the  overlying  gray  matter.  All  these 
collaterals,  as  well  as  finally  the  original  axon  itself,  ascend  through  the 


Fig.  28.  — Plexus  of  heavy  sensory  fibres  from  motor  cortex  of  cat  25  days  old.  A,  plexiform 
layer;  B,  layer  of  small  and  medium-sized  pyramids;  C'and  D,  layers  of  granules  and  superficial 
layer  of  giant  pyramids ;  E,  deep  layer  of  giant  pyramids ;  F,  layer  of  polymorphic  cells ;  a,  fibre 
from  white  matter ;  h,  ascending  collateral ;  c,  varicose  terminal  arborization ;  d,  fibre  directed  to 
the  plexiform  layer,  VFhich  appears  to  be  distinct  from  the  large  fibres. 


372  Santiago  Ramon  y  Cajal: 

polymorphic  layer,  dividing  once  or  twice,  then,  passing  obliquely  through 
intervening  layers,  form  an  arborization  of  heavy  fibres  within  the  layers 
of  small,  medium-sized,  and  large  pyramidal  cells.  However,  in  the  rat 
and  rabbit  these  branches  are  most  numerous  in  a  relatively  superficial 
plane,  which  corresponds  probably  with  the  granular  layer  of  the  human 
brain,  —  a  layer  that  is  not  differentiated  in  the  small  mammals.  We 
also  find  a  relatively  small  number  of  branches  that  ascend  to  the 
plexiform  layer.  As  to  the  cortical  distribution  of  this  plexus,  we 
may  also  place  on  record  a  fact  of  interest.  It  never  covers  the  whole 
cortex.  It  begins  to  appear  some  distance  from  the  median  fissure  and 
disappears  below  long  before  reaching  the  olfactory  area  or  limbic  lobe. 
I  have  never  observed  it  in  the  cortex  of  this  sulcus,  nor  in  the  anterior 
portion  of  the  frontal  lobe,  nor  even  in  the  region  of  the  auditory  or 
visual  centres. 

I  shall  return  to  this  matter  in  a  future  investigation,  for  I  think  it 
merits  most  thorough  study  ;  because,  if  it  can  be  confirmed  in  a  positive 
manner  and  by  other  methods,  we  shall  possess  a  criterion  by  which  to 
distinguish  between  areas  of  association  and  projection  in  the  cortex. 
The  projection  areas  will  probably  be  found  to  be  not,  as  Flechsig  thinks, 
those  possessing  fibres  that  go  to  the  corpus  striatum  (since  Dejerine 
and  others  have  discovered  these  fibres  in  the  so-called  association 
centres)  but  those  receiving  sensory  fibres.  At  the  same  time,  the 
association  centres  will  be  characterized  by  the  absence  of  these  direct 
sensory  connections.  At  any  rate,  I  believe  that  even  in  the  brain  of  the 
smallest  mammal  there  are  areas,  of  small  extent  it  may  be,  specialized 
to  store  up  the  images  or  residues  of  the  sensory  projection  centres.  It 
would  be  most  astounding  if  the  brains  of  the  small  mammals  possessed 
a  different  architecture  from  that  of  man,  taking  into  consideration  the 
fact  that  all  the  senses  have  the  same  essential  structure  in  all  mammals 
and  that  memory  —  visual,  tactile,  muscular,  etc.  —  is  just  as  necessary  to 
their  lives  as  to  our  own. 

The  sensory  plexus  is  highly  developed  in  gyrencephalous  mammals 
and  in  man.  I  have  found  it  well  impregnated  in  the  brains  of  infants 
at  birth  and  a  few  days  old.  Here  it  appears  made  up  of  large  fibres 
having  an  oblique  direction  and  a  flexuous  or  even  staircased  course. 
After  dividing  several  times  in  the  6th  and  5th  layers  they  give  rise  to  a 
singularly  extended  arborization  of  horizontal  fibres  distributed  chiefly 
to  the  layer  of  granules  or  small  stellate  cells.     We  thus  see  in  the  motor 


SensorirMotor  Cortex.  373 

cortex,  as  was  the  case  in  the  visual,  that  the  layer  of  granules  is  the 
principal  focus  of  sensory  impressions.  From  this  terminus  they  are 
propagated  by  the  numberless  cells  with  short  ascending  axons  to  the 
layers  above  and  especially  to  the  medium-sized  and  giant  pyramids. 
However,  it  must  be  acknowledged  that  the  sensory  plexus  is  not  so 
narrow  and  well  defined  as  tb  j  optic.  For,  although  its  greatest  density 
occurs  in  the  4th  iaj^er,  its  vjrminal  branches  divide  in  their  ascent 
to  the  superficial  layer  of  medium-sized  and  giant  pyramids.  The  fibres 
which  extend  up  to  the  small  pyramids  in  man  are  not  numerous.  It  is 
for  this  reason  that  I  cannot  agree  with  Bevan  Lewis  in  ascribing  to 
them  sensory  functions.  I  do  not  wish  to  be  understood  to  deny  the 
sensory  function  of  the  small  and  medium-sized  pryamids.  .  According  to 
my  view,  all  the  cells  of  the  motor  cortex  are  sensory  because  they  all, 
possibly,  come  into  contact  either  directly  (cells  of  the  3d,  4th,  and 
5th  layers)  or  indirectly,  through  the  intervention  of  cells  with  short 
axons,  with  sensory  terminal  arborizations.  But,  since  some  cells  send 
their  axons  to  the  pyramidal  tracts,  we  are  able  to  distinguish  them 
as  sensori-motor  cells  of  the  first  order.  The  others,  which  send  their 
neurites  to  other  motor  areas  of  the  brain,  possibly  effect  contact  with 
sensori-motor  cells  of  the  first  order  located  elsewhere.  These  cells  of 
indirect  sensori-motor  communication  we  may  be  warranted  in  calling 
sensori-motor  cells  of  the  second  order.  It  goes  without  saying  that  this 
distinction  is  purely  hypothetical ;  for  no  method  enables  us  to  determine 
the  precise  point  within  the  brain  where  the  axons  of  the  pyramidal  tracts 
of  the  corpus  callosum  or  of  bands  of  association  fibres  form  their  terminal 
arborizations. 

5.  Layer  of  the  Giant  and  Medium-sized  Pyramids. —  In  the  adult 
human  brain  stained  by  Nissl's  method,  a  section  of  the  motor  cortex 
reveals,  below  the  granular  layer,  a  layer  of  plexif orm  or  granular  aspect 
filled  very  thickly,  but  in  no  particular  order,  with  a  few  giant  and  a 
great  number  of  medium-sized  pyramids  (Fig.  29). 

Usually  the  giant  pyramids  are  located  near  the  4th  layer,  forming 
there  a  few  irregular  ranks.  Impregnated  by  Golgi's  method,  they 
appear  similar  to  the  same  cells  in  other  regions  of  the  cortex,  but  differ 
in  a  few  particulars.  The  body  is  generally  conical,  very  much  elon- 
gated, giving  rise  at  the  apex  to  a  large  trunk,  often  dividing  near  the 
cell,  which  terminates  in  the  1st  layer  in  the  usual  manner.  A  group 
of  long  complicated  dendrites  diverges  from  its  base,  and  from  the  sides 


374 


Switlayo  Ramon  y  Cajal : 


spring  several  very  long  horizontal  processes  which  subdivide  into  ter- 
minal brushes,  and  these,  intertwining  with  similar  structures  from 
neighboring  cells  of  the  same  level,  form  a  dense  and  very  characteristic 


Fig.  29. — Deep  layer  of  giant  pyramidal  cells  from  motor  cortex  of  infant  aged  20  days. 
A,  B,  pyramidal  cells ;  D,  C,  elements  with  short  axons. 

protoplasmic  plexus.  It  is  the  same  arrangement  we  already  know  so 
well  in  the  visual  cortex,  except  that,  instead  of  one  plexus,  there  are 
many.  The  axon  is  large  and,  after  giving  off  very  long  collaterals  to 
the  5th  and  6th  layers,  it  passes  on  to  become  a  medullated  fibre  of  the 
white  matter. 

The  medium-sized  pyramids  are  very  numerous,  much  scattered,  and 


Sensor ir Motor  Cortex.  375 

occur  in  greatest  profusion  in  the  lower  levels  of  the  layer.  They  do 
not  differ  in  character  from  the  giant  pyramids,  except  as  to  the  lateral 
somatic  dendrites,  which  are  few  and  not  characteristic. 

Besides  the  pyramidal  cells  the  5th  layer  contains  a  few  other  kinds 
of  elements.  From  the  point  of  view  of  their  morphology  the  following 
are  the  more  striking  types. 

(a)  Cells  which  form  Terminal  Nests.  —  These  cells,  very  similar  to 
those  which  give  rise  to  the  basket  fibres  of  the  cerebellum,  are  most 
numerous  in  the  5th  layer  between  or  below  the  giant  pyramids.  I  have 
found  them  also  in  the  layer  of  granules  or  small  stellate  cells. 

Their  volume  is  small,  similar  to  that  of  a  small  pyramid,  and  in  form 
they  appear  stellate  or  triangular  with  very  long  and  much-branched 
varicose  dendrites.  The  neurite,  however,  presents  the  most  distinctive 
feature.  It  ascends,  forking  close  to  its  origin,  and  breaks  up  into  a 
ramification  of  very  many  branches,  ascending,  oblique,  or  horizontal. 
After  a  few  subdivisions,  all  these  branches  make  their  way  to  the  giant 
and  medium-sized  pyramids  to  form  very  complicated  varicose  arboriza- 
tions close  around  their  cell  bodies  and  principal  processes,  after  the 
manner  of  the  terminal  baskets  of  the  cerebellum  or  the  nests  found  in 
Deiter's  nucleus.  Each  nest  contains  arborizations  from  several  cells,  and 
each  basket  cell  helps  to  form  a  large  number  of  nests  (Fig.  30,  d). 

(6)  Cells  with  a  Diffusely  Branched  Ascending  Axon.  —  This  is  a 
fusiform  or  stellate  cell  located  at  different  levels  of  the  5th  layer,  to 
which  it  sends  its  dendrites.  The  axon  ascends  to  the  superior  limits  of 
the  layer  where  it  forks,  and  its  terminal  branches  form  a  loose  horizon- 
tal arborization  of  an  enormous  extent  and  connected  probably  with  the 
deep  giant  pyramids  (Fig.  29,  C,  D). 

(c)  Small  Pyramids  with  Arched  Axons. — This  cell,  which  I  have 
studied  particularly  in  the  motor  cortex  of  the  cat,  is  entirely  similar  to 
the  element  which  we  found  in  the  6th  and  7th  layers  of  the  visual 
cortex.  The  cells  possess  a  fine  dendrite  which  ascends  to  the  first  layer, 
where  it  ends  in  a  very  modest  and  delicate  arborization.  Their  axon 
descends  and,  after  giving  off  a  few  relatively  long  recurrent  collaterals, 
appears  to  fork  and  end  in  the  midst  of  the  5th  layer.  The  branches 
which  spring  from  the  bend  of  the  arch  descend  in  some  cases,  but  I  have 
not  been  able  to  trace  them  down  to  the  white  matter. 

(c?)  Cells  with  Long  Ascending  Axon.  —  These  are  fusiform  or  tri- 
angular cells  with  long  polar  dendrites  which  never  reach  the  first  layer. 


376 


Santiago  Ramon  y  Cajal : 


Their  axon  arises  from  the  superior  surface  of  the  cell,  and,  after  giving 
off  a  few  branches  to  the  5th  and  4th  layers,  it  continues  its  ascent  to  the 
plexiform  layer  and  there  makes  its  terminal  arborization. 

6.    Layer  of  Polymorphic  Cells.  —  This  layer  contains  the  same  elements 
as  the  layer  of  the  same  name  (9th)  in  the  visual  cortex  (Fig.  31),  that 


Fig.  30.  —  Pericellular  terminal  arborizations  from  the  deep  layer  of  giant  pyramids,  motor 
cortex  (ascending  frontal  convolution)  of  infant  aged  25  days,  a,  axons  giving  rise  to  oblique 
and  horizontal  branches ;  b,  c,  d,  terminal  nests. 

is  to  say,  fusiform  cells  with  two  long  polar  dendrites,  triangular  cells,  and 
true  pyramids.  Their  axons  all  go  to  the  white  matter.  Their  ascend- 
ing trunks,  which  are  never  lacking,  become  very  attenuated  on  account 
of  the  branches  given  off  while  passing  through  the  4th  layer  and  reach 
the  1st  layer  as  an  exceedingly  delicate  fibril,  which  ends  in  a  fine, 
slightly  extended,  notably  varicose  dendritic  spray. 

In  Fig.  31,  I  have  reproduced  the  principal  types  of  cells  found  in  the 
polymorphic  layer.  Besides  the  medium-sized  pyramidal  and  triangular 
types  having  long  descending  axons  (Fig.  31,  A,  ^),  there  occur  other 


SensorirMotor  Cortex. 


377 


forms  in  great  numbers.     These  are  fusiform  or  triangular  cells  whose 
axons  penetrate  into  the  superposed  layers,  furnishing  to  them  a  great 


Fig.  31.  —  Principal  types  of  polymorphic  cells  from  motor  cortex  of  infant  aged  20  days.  A,  B, 
cells  with  long  axons  extending  to  white  matter ;  C,  D,  E,  fusiform  cells  with  ascending  axon ;  H, 
giant  stellate  cell. 

number  of  branches.     Some  of  these  axons  seem  to  end  in  the  deep  layer 
of  giant  pyramids,  but  others  appear  to  pass  beyond  this.     Finally,  there 


378  Santiago  Ramon  y  Cajal: 

is  no  lack  of  arachniforra  cells  (Fig.  31,  /),  cells  with  short  axon  of  the 
sensory  type  of  Golgi,  whose  axons  form  terminal  arborizations  in  the 
layer  under  consideration.  I  may  add  that  I  have  found  in  two  cases 
giant  stellate  cells  with  heavy  horizontal  axon  which  gives  off  collaterals 
(Fig.  31,  JST).  I  do  not  know  the  ultimate  fate  of  this  process  and  am 
unable  to  say  whether  these  scattering  cells  form  a  constant  feature  of  the 
motor  cortex. 

Cortex  of  Acoustic,  Olfactory,  and  Associational  Areas. 

Unfortunately,  my  own  researches  are  not  as  yet  in  a  very  advanced 
state  in  regard  to  these  important  cortical  centres.  So  that  any  in- 
formation that  I  can  give  must  necessarily  be  fragmentary  and  of  little 
value. 

The  acoustic  resembles  exactly  the  motor  cortex  as  to  general 
arrangement  of  cells  and  layers,  but  differs  from  it  in  a  few  pecu- 
liarities :  (1)  by  the  fineness  of  the  fibres  forming  the  plexus  at  the  level 
of  the  layer  of  granules  or  small  stellate  cells ;  (2)  in  the  profusion  of 
bipanicled  cells  with  their  very  delicate  and  complicated  neuritic  brushes  ; 
(3)  above  all,  by  the  presence  of  certain  special  cells  scattered  irregularly 
through  the  entire  thickness  of  the  cortex.  The  very  large  axon  of  these 
special  cells  extends  in  a  horizontal  or  oblique  direction,  but  I  have  not 
yet  been  able  to  determine  exactly  its  manner  of  termination.  These 
large  cells  are  fusiform  and  lie  horizontally.  From  their  polar  dendrites 
spring  a  number  of  fine  ascending  branches,  which  subdivide  repeatedly 
but  do  not  extend  up  as  far  as  the  plexiform  layer. 

The  olfactory  cortex,  that  of  the  limbic  lobe,  is  characterized  by  the 
following  peculiarities  :  (1)  the  enormous  development  of  the  plexiform 
layer  and  the  presence  in  it,  in  addition  to  its  usual  structures,  of  the 
antero-posterior  fibres  that  come  from  the  external  root  of  the  olfactory 
tract ;  (2)  the  absence  of  the  layers  of  small  pyramids  and  granules ; 
(3)  the  presence  of  certain  large  horizontal  cells  below  the  plexiform 
layer ;  (4)  the  peculiar  form  of  the  medium-  and  large-sized  pyramids 
which  emit  from  the  deep  end  of  the  cell  body  a  brush  consisting  of 
numerous  much  subdivided  dendrites ;  (5)  above  all,  the  fact  that  the 
sensory  plexus,  i.e.  the  fibres  which  come  from  the  olfactory  bulb,  makes 
its  terminal  arborization  exclusively  in  the  plexiform  layer  and  in  the 
most  superficial  portion  of  that  layer,  corresponding  to  that  of  the  small 


SensorirMotor  Cortex.  379 

pyramids.  This  significant  fact,  brought  to  light  by  the  studies  of 
Calleja,  shows  us  that  the  sensory  fibres  do  not  end  in  the  same  level 
of  the  cortex  in  all  regions.  Hence,  the  layer  specialized  to  serve  as 
substratum  for  the  phenomena  of  sensation  may  change  its  position  in 
different  sensory  areas. 

Our  task  is  now  drawing  to  its  close.  My  work  upon  the  topo- 
graphical structure  of  the  cortex  has  been  fragmentary  and  leaves 
much  to  be  desired.  Many  things,  in  fact,  are  still  undiscovered.  But, 
despite  the  very  incomplete  state  of  my  researches  and  the  narrow 
limits  of  the  field  they  cover,  I  may  draw  a  few  anatomico-j)hysiological 
conclusions,  of  which  the  chief  are  the  following  :  — 

And  first,  as  to  the  hierarchy  of  centres  in  the  cortex  of  the  human 
brain,  comparing  it  with  the  mammalian  brain,  we  may  call  to  mind  that, 
while  it  does  not  contain  wholly  new  elements,  it  presents  very  distinc- 
tive characteristics,  to  wit :  — 

1.  The  enormous  development  of  the  horizontal  cells  of  the  plexi- 
form  layer  and  the  considerable  length  of  their  so-called  tangential 
fibres. 

2.  The  great  abundance  of  cells  with  short  axons  scattered  through- 
out the  whole  cortex,  cells  which  form  special  varieties  by  reason  of 
differences  in  their  forms  and  the  directions  of  their  axons. 

3.  The  presence  of  cells  with  short  axons,  very  slender  (bipanicled 
spider  cells),  with  terminal  arborizations  whose  delicacy  is  not  approached 
by  anything  found  in  any  animal. 

4.  The  considerable  development  of  basilar  dendrites  of  the  pyram- 
idal cells. 

5.  The  presence  among  the  mid-layers  of  the  cortex  of  a  formation 
of  so-called  granular  cells,  a  kind  of  focus  occupied  by  enormous  num- 
bers of  pyramids  with  short  axons  descending,  arched,  and  ascending. 
This  granular  formation  is  present  in  gyrencephalous  mammals,  but  in 
them  it  is  very  poor  in  cells  with  short  axons  and  in  small  pyramids. 
In  the  smooth-brained  animals  it  is  almost  wholly  lacking. 

The  human  cortex  has  evolved,  accordingly,  along  three  different 
lines :  by  multiplying  cells  with  long  axons  and,  above  all,  those  with 
short  axons ;  by  decreasing  the  volume  of  cells  and  the  diameter  of  cer- 
tain fibres  in  order  to  make  possible  within  the  limits  of  space  a  deli- 
cate and  greatly  improved  organization ;  finally,  by  varying  and  infinitely 


380  Santiago  Ramon  y  Cajal : 

complicating  the  external  morphology  of  the  nerve  elements,  undoubt- 
edly with  the  purpose  of  multiplying,  in  correspondence  with  their 
complexity,  functional  associations  of  all  kinds. 

As  to  differences  and  analogies  in  regional  structure,  the  following 
propositions  may  be  regarded  as  established :  — 

1.  The  sensory  as  well  as  the  so-called  associational  areas  are  made 
up  by  a  combination  of  two  orders  of  structural  factors.  The  first 
order  consists  of  common  factors,  which  show  very  little  modification. 
They  are  represented  by  the  plexiform  layers  and  the  layers  of  pyram- 
idal and  polymorphic  cells.  The  second  order  comprises  special  fac- 
tors, structures  peculiar  to  each  cortical  area.  Their  chief  anatomical 
feature  resides  especially  in  the  granular  layer  and  is  related  mainly 
to  the  presence  of  particular  centripetal  fibres  and  of  special  types  of 
cells  with  long  axons  (stellate  cells  of  different  Idnds). 

2.  It  seems  probable  that  the  common  factors  perform  functions  of 
a  general  order  concerned,  possibly,  with  ideas  of  representations  of 
all  kinds  of  movements  related  to  the  special  sensations  of  which  the 
cortical  region  is  the  seat.  It  seems  also  probable  that  the  special 
anatomical  factors  of  the  sensory  areas  perform  the  function  of  elab- 
orating specific  sensations  (sensation  of  seeing,  hearing,  etc.)  and  also 
of  conveying  sensory  residues  to  the  so-called  association  centres,  where 
they  may  be  transformed  into  latent  images. 

3.  Each  sensory  cortical  centre  receives  a  special  category  of  nerve 
fibres  (fibres  of  central  sensory  tracts).  Their  cells  of  origin,  as  has  been 
shown  by  the  researches  of  v.  Monakow,  Flechsig,  v.  Bechterew,  and 
many  others,  reside  in  the  particular  nuclei  of  the  medulla,  corpora  quad- 
rigemina,  and  optic  thalami.  It  is  precisely  the  presence  of  these  sen- 
sory fibres  of  the  second  order  that  constitutes  the  prime  anatomical 
characteristic  of   the  centres  of  sensation  or  projection. 

4.  The  absence  of  these  sensory  fibres,  which  come  from  the  corona 
radiata,  may  be  used  in  all  mammals  to  distinguish  the  so-called  associ- 
ation centres.  These  centres,  which  exist  even  in  the  mouse,  also  have  a 
nerve  fibre  plexus  distributed  among  their  median  layers  (layer  of  gran- 
ules in  the  association  areas  in  man).  The  fibres,  however,  which  consti- 
tute them  are  very  fine  and  appear  to  come  from  sensory  centres  of  the 
brain.  Possibly  the  cells  about  which  these  sensorio-ideational  fibres 
terminate  represent  the  substratum  or,  at  any  rate,  the  first  link  in  the 
chain  of  nerve  elements  whose  function  is  the  representation  of  ideas. 


Se7isorir Motor  Cortex.  381 

5.  Since  we  have  seen  that  each  afferent  fibre  in  the  sensory  cortex 
comes  into  contact  with  an  extraordinary  number  of  nerve  cells  appar- 
ently scattered  without  any  order,  we  must  suspect  that  these  relations 
conform  to  the  preconceived  design  of  a  well-determined  and  constant 
organization. 

As,  at  present,  it  seems  to  be  impossible  to  discover  these  relations, 
we  may  surmise  that  each  sensory  fibre  comes  into  contact,  directly  or 
through  other  cells,  solely  with  those  pyramids  whose  stimulation  is  nec- 
essary in  order  to  effect,  after  the  manner  of  the  reflex  arc,  movements 
coordinated  and  intentional.  We  may  also  surmise  (supposing  that  the 
stellate  cells  of  the  tactile  and  visual  cortex  form  the  link  between  the 
sensory  and  ideational  centres)  that  each  sensory  afferent  fibre,  bringing 
a  unit  of  sensation  (the  impression  received  by  a  cone  of  the  retina  or  by 
the  terminal  arborization  of  any  peripheral  nerve  fibre),  enters  into  rela- 
tion exclusively  with  the  group  of  nerve  cells  entrusted  with  the  func- 
tion of  conveying  this  impression  to  a  particular  point  in  the  associational 
cortex. 

Many  other  hypotheses  are  possible,  but  I  must  conclude  for  fear  of 
tiring  your  kind  and  sympathetic  attention  and  exhausting  your  patience. 
I  fear  that  I  have  already  made  too  free  use  of  hypotheses  and  have  pre- 
tended to  fill  the  gaps  of  possible  observations  with  arbitrary  supposi- 
tions. 

It  is  a  rule  of  wisdom,  and  of  nice  scientific  prudence  as  well,  not  to 
theorize  before  completing  the  observation  of  facts.  But  who  is  so 
master  of  himself  as  to  be  able  to  wait  calmly  in  the  midst  of  darkness 
until  the  break  of  dawn  ?  Who  can  tarry  prudently  until  the  epoch  of 
the  perfection  of  truth  (unhappily  as  yet  very  far  off)  shall  come  ?  Such 
impatience  may  find  its  justification  in  the  shortness  of  human  life  and 
also  in  the  supreme  necessity  of  dominating,  as  soon  as  possible,  the  phe- 
nomena of  the  external  and  internal  worlds.  But  reality  is  infinite  and 
our  intelligence  finite.  Nature  and  especially  the  phenomena  of  life  show 
us  everywhere  complications,  which  we  pretend  to  remove  by  the  false 
mirage  of  our  simple  formulae,  heedless  of  the  fact  that  the  simplicity 
is  not  in  nature  but  in  ourselves. 

It  is  this  limitation  of  our  faculties  that  impels  us  continually  to 
forge  simple  hypotheses  made  to  fit,  by  mutilating  it,  the  infinite  uni- 
verse into  the  narrow  mould  of  the  human  skull,  —  and  this,  despite  the 
warnings  of  experience,  which  daily  calls  to  our  minds  the  weakness,  the 


382        Santiago  Ramon  y  Cajal :    Sensor ir Motor  Cortex. 

childishness,  and  the  extreme  mutability  of  our  theories.  But  this  is  a 
matter  of  fate,  unavoidable  because  the  brain  is  only  a  savings-bank 
machine  for  picking  and  choosing  among  external  realities.  It  cannot 
preserve  impressions  of  the  external  world  except  by  continually  simpli- 
fying them,  by  interrupting  their  serial  and  continuous  flow,  and  by 
ignoring  all  those  whose  intensities  are  too  great  or  too  small. 

I  cannot  conclude  this,  my  third  and  last  lecture,  without  a  word  of 
tribute  to  this  great  people  of  North  America, — the  home  of  freedom  and 
tolerance,  —  this  daring  race  whose  positive  and  practical  intelligence, 
entirely  freed  from  the  heavy  burdens  of  tradition  and  the  prejudices  of 
the  schools,  which  weigh  still  so  heavily  on  the  minds  of  Europe,  seems 
to  be  wonderfully  endowed  to  triumph  in  the  arena  of  scientific  research, 
as  it  has  many  times  triumphed  in  the  great  struggles  of  industrial  and 
commercial  competition. 


384  Angelo  Mosso : 

this,  that  at  birth  the  organs  which  effect  movement,  over  which  the  brain 
later  exercises  its  authority,  are  not  yet  complete. 

The  muscles  of  the  adult  human  being  are  thirty-seven  times  as  heavy 
as  those  of  the  newborn  child,  while  the  brain  of  the  former  is  only 
3.76  times  as  heavy  as  that  of  the  latter. 

It  had  been  long  known  also  that  the  brain  of  man  slowly  increases  in 
weight  up  to  the  fortieth  year.  Recently  Kaes  ^  has  shown  that,  up  to 
the  fortieth  year,  there  are  formed  in  the  cerebral  convolutions  new  plex- 
uses of  nerve  fibres,  which  are  lacking  in  younger  brains. 

Excitation  of  the  senses  and  impulses  to  movement  hasten  the  devel- 
opment of  the  nerves  in  question.  The  experiments  of  Ambronn  and 
Held^  have  shown  that,  if  one  eye  of  a  newborn  kitten  is  opened  to 
the  light,  the  other  remaining  closed,  the  optical  fibres  of  the  eye  which 
is  stimulated  by  the  light  are  more  quickly  surrounded  with  myelin  than 
those  of  the  other.  Another  important  fact  is  that  the  motor  nerve 
fibres  are  complete  earlier  than  the  sensory. 

These  facts  we  must  apply  to  pedagogy.  Only  that  science  can  show 
how  injurious  is  precocious  instruction  for  the  development  of  the  child. 

If  we  wish  to  hasten  the  maturity  of  the  brain,  we  must  decide  whether 
the  formation  of  the  myelin  can  better  be  hastened  by  stimulations  of  the 
senses  and  intellectual  work,  or  better  by  muscular  exercises.  The  latter 
way  seems  to  me  the  more  natural.  We  must,  therefore,  to  begin  with, 
consolidate  the  motor  nerve  paths  which  develop  first,  and  after  that  seek 
to  develop  the  portion  of  the  brain  concerned  with  intellectual  work. 
Modern  views  show  a  tendency  to  confirm  what  the  great  philosophers  of 
Greece  already  recognized,  viz.,  that  children  ought  to  begin  to  read  and 
write  only  with  the  tenth  year.  The  conviction  is  again  slowly  maturing 
that  our  children  begin  to  learn  too  early,  that  it  is  injurious  for  the 
development  of  the  brain  to  be  fettered  to  the  school-desk  when  only  five 
or  six  years  old.  The  conviction  is  slowly  making  its  way  that  no  more 
time  should  be  devoted  to  intellectual  work  than  to  muscular  exercise. 
The  modern  education  of  youth,  however,  resembles  more  an  artificial 
hothouse  culture  than  a  natural  training  of  the  human  plant. 

11. 

The  fact  observed  by  me  that  in  man  the  phenomena  of  intellectual 
fatigue  are  identical  with  those  of  muscular  fatigue,  caused  me  to  inquire 
whether  or  not  the  conscious  processes  and  those  of  movement  are  identi- 


Psychic  Processes.  385 

cal  processes,  which  take  place  in  like  cells,  or,  perhaps,  alternately  in  one 
and  the  same  cell. 

The  new  phrenology  exhibits  a  tendency  to  localize  the  mental  func- 
tions, but  the  old  idea,  which  distributed  the  nervous  functions  over  the 
whole  cerebral  cortex,  does  not  yet  acknowledge  its  defeat,  and  what  I 
have  to  say  to-day  will  show  that  there  exists  an  intimate  connection 
between  the  conscious  processes  and  muscular  exercise. 

Doubtless,  there  are  regions  known  in  the  brain  which  are  traversed 
by  the  will  impulse  which  sets  certain  muscle  groups  in  motion,  but  they 
are  the  junctions  of  roads,  they  are  the  tracks  upon  which  the  trains  run, 
not  the  stations  where  the  trains  are  formed,  and  where  they  receive  the 
will  impulse.  In  fact,  in  cases  where  it  was  possible  to  stimulate  electri- 
cally the  motor  region  of  the  human  cerebral  cortex,  the  subject  declared 
that  he  felt,  in  that  part  of  the  body  in  which  the  current  caused  a  mus- 
cular contraction,  sensations  which  resembled  the  creeping  or  running  of 
ants. 

If  the  so-called  motor  region  of  the  brain  is  destroyed,  it  is  found  that 
a  change  of  sensibility  also  takes  place.  These  facts  sufifice  to  show  that, 
up  to  the  present,  no  absolute  local  separation  of  movement  and  sensibil- 
ity is  demonstrable.  Moreover,  all  agree  that  every  will  impulse  is  joined 
to  the  idea  of  the  movement  to  be  executed. 

If,  in  a  monkey,  the  roots  of  the  sensory  nerves  which  go  to  the  arm 
are  severed,  the  animal  no  longer  moves  the  hand  spontaneously,  although 
the  voluntary  nerve  paths  are  uninjured,  because  the  uhi  consistam  of 
sensibility  is  lacking.  Our  mechanisms  are  so  complete  that  the  move- 
ment-command is  never  given  by  the  cells  without  a  clear  idea  of  the 
place  where  it  is  to  be  carried  out. 

In  every  voluntary  movement  there  exists  between  the  periphery  and 
the  centre  such  an  intimate  connection  that  patients  who  have  lost  the 
muscle  sense  can  contract  the  muscles  of  the  hand  around  an  object  and 
keep  them  contracted,  as  long  as  they  look  at  the  object.  So  soon,  how- 
ever, as  they  turn  their  eyes  away,  the  muscles  instantaneously  relax.  For 
a  movement  impulse  to  express  itself,  it  must  be  controlled  by  the  sensory 
nerves ;  for  the  will  and  the  sensibility  are  functions  inseparably  con- 
nected with  each  other. 

ni. 

Attention,  which  has  been  called  an  internal  sense,  shows  really  in  the 
best  way  how  isolation  from  the  influence  of  the  external  world  is  possi- 
2  c 


386  Angelo  Mosso : 

ble  in  the  study  of  psychic  phenomena.  Attention  is  the  most  intense 
activity  of  the  mind,  and  yet  we  all  know  that  we  are  not  capable  of 
absolutely  controlling  it.  The  more  or  less  favorable  disposition  for 
intellectual  work,  which  we  perceive  on  certain  days  and  at  certain  hours, 
awakes  the  suspicion  that  attention  itself  is,  to  a  great  extent,  conditioned 
by  internal  reflex  phenomena. 

I  have  already  shown  in  my  writings  *  that,  in  a  state  of  attention,  the 
respiration  becomes  slower  and  deeper,  the  blood-vessels  in  the  forearm 
and  in  the  foot  contract,  the  blood  flows  more  abundantly  to  the  centre, 
the  form  of  the  brain  and  arm  pulse  changes,  and  the  activity  of  the  heart 
is  increased. 

In  the  state  of  attention,  moreover,  there  exist  an  increased  secretion 
of  sweat,  a  greater  consumption  of  the  organism  —  the  blood  is  poisoned 
by  the  products  of  intellectual  fatigue.^ 

Attention  produces  not  only  the  same  chemical  effects  and  the  same 
fatigue  as  muscular  exertion  does,  but  we  feel  also,  when  we  are  attentive 
to  anything,  the  characteristic  muscular  strain  on  the  occiput,  the  fore- 
head, and  other  parts  of  the  body. 

One  of  the  characteristic  phenomena  of  attention  is  its  periods,  which 
have  been  so  well  studied  by  Wundt  and  his  pupils, — periods  which 
exhibit  a  great  resemblance  to  those  observed  by  Dr.  W.  P.  Lombard^ 
in  the  case  of  continued  muscular  contraction.  Under  the  direction  of 
Dr.  G.  Stanley  Hall,  Lindley'''  has  investigated  the  involuntary  move- 
ments which  we  make  when  we  think  of  anything,  muscular  contractions 
of  the  face,  hands,  and  feet.  These  movements  are  like  those  which  we 
make  during  muscular  exertion. 

We  cannot  force  the  attention  to  fix  itself  upon  one  object  contin- 
ually, because  it  quickly  becomes  exhausted,  and  renews  itself  only  when 
a  new  object  is  offered  it,  when  new  paths  for  its  activity  are  opened. 
It  is  not  we  who  direct  the  attention.  We  can  only  indicate  to  it  the 
direction  which  it  is  to  take  according  to  our  wishes.  After  that  it  is 
free  and  does  what  it  pleases ;  it  flits  about  like  a  butterfly  on  the  path 
which  we  have  pointed  out  for  it. 

The  excitability  of  artists,  the  peculiarity  of  their  character,  show  that 
in  them  the  involuntary  movements  are  more  easily  executed,  and  that 
intelligence  and  mobility  increase  together.  But  the  fact  that  artists  see 
objects  in  a  particular  way,  and  that  the  thing  seen  by  artists,  like  that 
seen  by  litterateurs,  is  retained  by  the  memory  in  very  characteristic  fash- 


Psychic  Processes.  387 

ion,  proves  that  attention  works  in  a  different  way  with  them.  The 
plastic  talent  of  southern  peoples,  the  ease  of  their  movements,  their  more 
lively  gestures,  the  more  intense  expression  of  their  emotions,  disclose  to 
us  the  nature  of  the  artists'  genius.  I  believe,  however,  that  there  is  also 
contained  in  attention  an  emotional  factor. 

IV. 

Great  impressionability  and  the  capacity  to  fix  the  attention  for  a 
longer  time  are,  doubtless,  two  of  the  chief  conditions  for  artistic  genius. 
But  I  believe  also  that  the  exercise  of  the  hands  exerts  an  influence  upon 
the  development  of  the  mind. 

During  the  first  epoch  of  the  Renaissance,  the  greatest  artists  of 
Florence  were  all  apprentices  in  the  workshops  of  the  goldsmiths.  Luca 
della  Robbia,  Lorenzo  Ghiberti,  Filippo  Brunelleschi,  Francia,  Domenico 
Ghirlandajo,  Sandro  Botticelli,  Andrea  del  Sarto,  —  to  mention  only  a  few 
examples,  —  performed,  during  their  apprenticeship,  the  simplest  labors 
in  the  workshop  of  a  goldsmith.  But  the  exercise  with  which  they 
gained  their  manual  dexterity  surely  influenced  also  the  development 
of  their  genius. 

In  the  beginning  of  the  sixteenth  century  this  school  ended,  but  from 
the  pedagogical  standpoint  it  is  still  worth  studying.  If  I  may  be  per- 
mitted to  express  an  opinion,  I  would  say  that  the  manual  dexterity 
favored  by  this  labor  contributed  much  to  the  development  of  the  great 
masters  of  genius. 

A  fact  which  cannot  be  doubted  is  the  manysidedness  of  genius  which 
some  Italians  of  the  Renaissance  possessed,  and  which  has  never  again 
appeared  with  like  copiousness. 

Giotto  was  painter,  sculptor,  and  architect.  Leonardo  da  Vinci  was  a 
celebrated  musician,  a  great  painter,  an  engineer,  an  architect,  a  man  of 
letters  and  of  science.  Andrea  del  Verrocchio  was  goldsmith,  sculptor, 
engraver,  architect,  painter,  and  musician.  These  facts  are  to  be  read  in 
many  histories  of  art.  An  incomparable  example,  however,  is  Michel- 
angelo. For  twelve  years  he  studied  anatomy  on  the  cadaver,  and  after- 
wards painted  the  Sixtine  Chapel  and  executed  the  tombs  of  the  Medici 
and  the  dome  of  St.  Peter's. 

In  the  artist,  better  than  in  other  human  beings,  is  seen  the  inti- 
mate connection  between  the  psychic  processes  and  muscular  exercise. 
Power   of   resistance   against   fatiguing   labors,  dexterity,  and   capacity 


388  Angelo  Mosso  : 

for  concentration,  are  the  secret  of  their  marvellous  life.  I  am  con- 
vinced that  muscular  movements  have  formed  the  omnipotence  of  genius, 
just  as,  vice  versd,  intellectual  exercises  effect  advantageously  the  develop- 
ment of  the  muscles.  Michelangelo  ground  his  colors  himself.  Raphael, 
while  as  an  engineer  in  Rome  he  carried  on  excavations  and  painted 
the  rooms  of  the  Vatican,  wrote  a  treatise  on  how  the  smoking  of 
the  chimney  in  the  kitchen  of  a  prince  might  be  prevented.  As  Vasari 
relates,  Perino  del  Vaga  made  every  mechanical  object;  he  fabricated 
often  trumpeters'  pennons,  portieres,  drapery,  flags,  embroidery,  and  carv- 
ing, and  painted  sarcophagi.  He  was  a  great  painter,  and  his  stucco 
works  belong  to  the  most  valuable  of  the  Renaissance  period.  Even  if 
the  genius  of  these  mighty  men  will  remain  a  secret  for  all  time,  yet 
we  can  say  this  much,  that  their  hand  was  just  as  dexterous  as  their  mind 
was  lofty. 

These  men,  who  are  the  greatest  representatives  of  our  race,  have 
carried  the  dexterity  of  their  hands  to  the  highest  degree  of  perfection. 
They  were  simple  workers,  who,  laboring  untiringly  with  their  hands, 
lifted  the  human  mind  to  the  highest  ideals  of  beauty. 

If  the  Greeks  excelled  all  other  peoples  in  genius,  it  was  because  they 
paid  more  attention  than  did  the  others  to  bodily  exercise ;  they  brought 
gymnastics,  the  study  of  bodily  positions  and  bodily  exercise,  to  a  height 
which  has  never  been  reached  by  other  peoples  since  their  day. 

V. 

Our  brain  possesses  probably  more  substance  than  we  generally  use, 
so  that  a  not  inconsiderable  part  of  it  may  be  looked  upon  as  an  organ  of 
luxury.  The  fact  observed  by  me,  that  we  breathe  in  more  air  than  is 
necessary,  together  with  the  fact  observed  much  earlier,  that  we  eat  much 
more  than  we  need,  allows  us  to  designate  as  luxury  all  that  is  not  abso- 
lutely necessary. 

Our  brain  has  on  the  average  about  a  milliard  of  nerve  cells.  Many 
men  have  more,  and  others  less  brain  substance,  without  it  being  possible 
to  detect  a  difference  in  the  intensity  of  their  psychic  processes. 

Large  and  heavy  brains  are  often  found  in  men  who  do  not  make  full 
use  of  them.  Such  a  brain  was  that  of  Rustan,  which  Rudolphi  has 
described.  It  weighed  2222  gr.,  while  that  of  Helmholtz^  weighed 
only  1420  gr.  The  brain  of  the  unknown,  commonplace  individual, 
Rustan,  was  therefore  802  gr.   heavier  than  that  of  Helmholtz.     The 


Psychic  Processes.  389 

great  facility  with  which,  in  the  case  of  partial  destruction  of  the  brain, 
the  individual  parts  can  substitute  one  another  has  been  demonstrated 
by  Flourens  and  Goltz. 

Not  all  the  brain  cells  work  simultaneously,  but  they  relieve  one 
another  probably  with  such  punctuality  that  only  under  certain  conditions 
do  we  notice  that  some  groups  are  fatigued. 

That  this  relief  process  exists  can  be  argued  from  the  fact  that  the 
nerve  cells  offer  only  a  very  small  resistance  to  fatigue. 

The  attention  itself  works  in  periods  of  activity  and  rest.  These 
periods  have  been  observed  in  the  case  of  the  sense  of  sight,  as  well  as  in 
the  senses  of  hearing,  taste,  and  touch.  Since,  as  Bowditch  has  shown, 
the  nerves,  as  such,  do  not  become  fatigued,  we  must  ascribe  such  fluctua- 
tions to  the  centre. 

If  we  close  one  eye,  and  with  the  other  look  at  an  equally  illuminated 
wall  or  the  sky,  we  notice  that  the  visual  field  now  darkens,  now  lights 
up  again. ^  The  dark  color  becomes  green,  yellowish,  or  blue,  and  appears 
in  regular  intervals,  5-12  times  a  minute.  These  periods  vanish  as 
soon  as  the  eye  in  attention  is  directed  towards  a  certain  object. 
I  do  not  believe  that  this  phenomenon  arises  from  the  movement  of  the 
blood-vessels,  for  it  appears  only  when  we  look  with  one  eye.  I  am  of 
the  opinion  that  it  points  to  a  relief -process  in  cerebral  activity,  and  to  a 
period  during  which  a  slight  fatigue  of  the  brain  cells  takes  place,  if  the 
latter  are  not  incited  by  the  attention  to  more  intense  labor.  Our  atten- 
tion turns  automatically  now  to  one,  now  to  the  other  eye.^^ 

There  exists  a  remarkable  agreement  between  the  periods  of  activity 
and  rest  of  the  brain  cells  and  of  the  sympathetic  system.  If  we  investi- 
gate the  movements  of  the  blood-vessels  with  the  plethysmograph,ii  and 
also  the  movements  of  the  bladder,^  we  notice  great  undulations,  coincid- 
ing with  some  respiratory  movements.  In  the  curves  also,  observed  in 
man  and  animals  when  the  blood  pressure  is  investigated,  these  fluctua- 
tions, which  were  first  described  by  Traube,  are  seen.  I  myself  have 
shown  that  the  respiratory  curve  exhibits  periods  of  greater  and  less 
activity.  These  fluctuations  are  particularly  characteristic  in  mountain 
sickness.  With  each  period  of  rest  the  excitability  of  the  nervous  centres 
is  decreased. 

From  all  these  phenomena  it  seems  to  follow  that  the  nerve  cells  have 
only  a  small  power  of  resistance,  and  that  they  show  on  the  average  every 
ten  seconds  a  tendency  to  rest. 


390  Angelo  Mosso : 

I  have  further  been  able  to  show,  by  means  of  the  ergograph,  that  to 
strongly  contract  the  hand  suffices  to  induce  in  the  brain  the  first  symp- 
toms of  fatigue,  and  that  a  few  seconds  of  rest  are  enough  to  make  the 
nerve  cells  capable  of  functioning  again. 

The  very  short  duration  of  the  capacity  to  resist  in  the  nerve  cells 
makes  it  plain  that  the  brain  must  necessarily  possess  a  great  number  of 
cells.  It  is  the  task  of  pedagogy  to  show  how  the  brain  cells  can  most 
fitly  be  employed  for  the  welfare  of  the  individual  and  of  society. 

It  is  already  well  known  that  the  barbarians  were  able  to  learn  foreign 

languages  with  greater  facility  than  the  Greeks  and  Romans.  ^^     When  we 

say  of  young  peoples  that  they  will  some  day  excel  us  in  literature,  as  in 

art  and  in  science,  we,  unconsciously  perhaps,  intimate  thereby  that  their 

brain  still  possesses  tracts  of  virgin  soil,  which,  with  later  cultivation, 

will  become  fertile. 

VI. 

The  more  mobile  the  extremities  of  an  animal  are,  the  more  in- 
telligent it  is.  Among  all  birds  the  parrot  is  the  most  intelligent,  because 
it  makes  more  use  than  do  other  birds  of  its  legs,  beak,  and  tongue. 
The  elephant  is  more  intelligent  than  all  other  wild  animals,  because 
he  makes  use  not  only  of  his  legs,  but  also  of  his  snout,  as  organs  of 
movement. 

Another  consideration  :  The  most  mobile  parts  of  the  body  are  at  the 
same  time  the  most  sensitive,  e.g.  the  tongue,  the  hand,  the  snout.  This 
increased  sensitiveness  depends  neither  on  a  more  numerous  ramification 
of  nerves,  nor  on  the  more  complicated  character  of  the  end  organs,  but 
arises  from  the  fact  that  the  brain  itself  is  more  irritable,  as  shown  by 
the  passions  of  animals,  which  are  more  violent  the  more  mobile  the 
creature  is. 

Romanes  ^*  has  already  said  that  the  higher  intelligence  of  monkeys  and 
the  highest  intelligence  of  man  are  related  to  a  more  perfect  instrument 
of  motion,  viz.  the  hand,  in  which  the  ideal  of  perfection  seems  to  have 
been  reached. 

The  cephalopods,  which  have  eight  arms,  formed  of  muscle-substance 
and  provided  with  suckers,  stand,  among  the  molluscs,  nearest  to  the 
vertebrates  on  account  of  their  strength  and  power  of  movement.  It  was 
movement,  probably,  that  developed  their  brain-ganglia,  for  these  are 
larger  in  the  cephalopods  than  in  the  other  molluscs.  As  they  possess  a 
good  memory  and  a  high  intelligence,  so  they  also  exhibit  more  intense 


Psychic  Processes.  391 

emotions,  as  may  be  seen  from  the  great  facility  with  which  the  color  of 
their  skin  changes. 

The  mutual  relation  of  intelligence  and  movement  is  one  of  the  most 
constant  factors  in  nature.  The  movements  always  change  when  the 
intelligence  changes.  We  need  only  consider  the  gait  of  the  Indians  in 
order  to  convince  ourselves  of  the  truth  of  my  assertion.  Their  walk  is 
characteristic,  being  heavier  and  slower  than  ours.  Microcephalic  indi- 
viduals have  an  awkward  gait,  and  an  inconsiderable  dexterity  in  the 
movement  of  the  hands.  This  change  in  movement  is  still  more  striking 
in  the  case  of  idiots. 

In  some  parts  of  Italy  and  of  Switzerland  there  are  many  cretins.  On 
my  frequent  Alpine  excursions,  I  was  often  able  to  recognize  by  their  gait 
the  degree  of  intelligence  of  persons  who  were  near  me.  I  have  con- 
vinced myself  of  the  fact  that  the  first  signs  of  cretinism  can  be  detected 
in  the  heavy  gait,  the  arched  vertebral  column,  and  the  manner  of  moving 
the  arms  in  walking. 

VII. 

Neither  anatomy  nor  physiology  has  hitherto  been  able  to  decide 
whether  like  brain  cells  have  different  functions,  or  whether  all  cells 
perform  the  same  service. 

Since  neither  chemically  nor  by  the  use  of  the  strongest  microscopes 
can  we  demonstrate  differences  in  the  nerve  cells  of  the  cerebral  cortex, 
it  is  therefore  probable  that  none  such  exist.  Hence,  I  believe  that  the 
psychic  functions  cannot  be  separated  from  the  motor,  that  rather  the 
psychic  phenomenon  and  that  which  imparts  the  movement  impulse  both 
have  their  seat  in  the  same  cell.  How  closely  connected  thought  and 
movement,  consciousness  and  muscular  activity,  are,  is  best  seen  in  the 
phenomena  of  sleep.  If,  shortly  before  going  to  sleep,  we  hold  a  book  or 
some  other  object  in  the  hand,  we  notice  that  the  object  falls,  the  muscles 
relaxing,  the  moment  consciousness  ceases.  The  significance  of  the  fact 
emphasized  here  is  not  decreased  by  the  phenomena  of  movement  observed 
in  somnambulists  and  individuals  who  have  been  hypnotized.  It  is  well 
known  that  one  can  ride  and  walk  when  asleep.  By  practice  one  can 
learn  to  play  the  pianoforte  without  distinguishing  the  individual  finger- 
movements.  Some  can  play  an  instrument  when  asleep.  But  these  are 
not  voluntary,  but  instinctive  and  reflex  movements. 

In  a  diseased  arm,  in  which  the  muscles  have  been  atrophied,  the 
sensitiveness  of  the  fingers  is  simultaneously  improved  if  one  seeks  to 


392  Angela  Mosso : 

remove  the  atrophied  condition  of  the  muscles  by  exercises  in  contrac- 
tion. 

When  the  brain  has  been  fatigued  by  exclusively  intellectual  activity, 
the  sensitiveness  of  the  hand  and  direct  irritability  of  the  muscles  are 
also  decreased.  These  observations  force  us  to  the  assumption  that  the 
intelligence,  the  sensitiveness,  and  the  movement  are  phenomena  which 
cannot  be  separated  from  each  other,  that  their  fusion  and  their  con- 
nection belong  to  the  conditions  which  permit  us  to  comprehend  the 
nature  of  the  mind. 

Imbecile  signifies  weak  in  body,  but  particularly  weak  in  mind.     In 

Latin,  however,  in  hacillum  means  "leaning  on  a  staff."     The  ancients 

have  thus  understood  the  relations  in  question  better  than  I  am  able  to 

express  them  in  words. 

vm. 

It  is  well  known  that  an  injury  on  a  certain  spot  in  the  left  temporal 
lobe  of  the  brain  carries  with  it  the  loss  of  speech.  Forty  years  ago 
Broca  first  described  a  case  of  this  kind.  At  the  autopsy  of  a  man  who 
had  lost  his  speech,  whose  right  arm  and  leg  were  paralyzed,  and  who, 
besides,  exhibited  disturbances  of  intelligence,  there  was  found  a  broad 
and  deep  depression  of  the  brain  substance,  extending  from  the  Sylvian 
fissure  to  that  of  Rolando.  Afterward  appeared  the  celebrated  treatises 
of  Broca,  which  form  an  imperishable  monument  in  the  history  of  cerebral 
localization.  It  is  the  merit  of  James  to  have  shown  that  the  motor 
impulse  develops  itself  before  the  appearance  of  language  in  the  convolu- 
tions of  the  left  cerebral  hemisphere. 

In  our  development  gestures  and  other  movements  appear  first ;  then, 
later,  the  sounds  of  language. 

It  is  not  the  process  of  consciousness  which  makes  our  hands  dex- 
terous, but  perhaps  the  movements  of  the  right  extremities,  which  effect 
the  higher  psychic  development  of  the  left  cerebral  hemisphere. 

The  influence  of  the  hand  upon  the  development  of  language  is  evi- 
dent from  the  fact  that  an  aphasic  patient  is  made  to  write  in  order  that 
he  may  gradually  regain  the  power  of  speech. 

The  relation  between  muscular  movements  and  conscious  processes  is 
so  intimate  that  when  the  arms  and  hands  of  a  hypnotized  person  are 
brought  into  certain  positions  and  certain  muscles  by  external  contact 
made  to  contract,  certain  emotions  are  induced  corresponding  to  those 
muscular  contractions.  Here,  then,  intellectual  processes  are  certainly 
effected  by  external  muscular  activity. 


Psychic  Processes.  393 

There  is  no  doubt  that  the  first  human  beings  were  dumb,  and  that 
men  for  a  long  time  made  use  of  gesture-language  for  purposes  of  mutual 
understanding  before  they  discovered  sound-language.  The  child,  too, 
before  it  is  able  to  speak,  expresses  itself  by  gestures.  It  observes  the 
looks  of  its  parents  and  of  the  persons  who  speak  to  it,  in  order  to  com- 
prehend the  meaning  of  the  words  heard.  Pantomime  is  the  heightened 
expression  of  the  involuntary  movements  which  accompany  the  individual 
phases  of  mental  activity.  In  the  hieroglyphs  of  the  Egyptians  and  in 
the  representations  on  Greek  vases  we  recognize  the  gestures  and  the 
involuntary  movements  which  men  made  more  than  three  thousand 
years  ago. 

IX. 

Leonardo  da  Vinci,  in  his  treatise  on  painting,  had  already  attempted 
to  describe  the  passions  by  detailing  how  to  represent  a  man  in  a  state  of 
rage  and  despair.  The  first  men  who  were  able  to  make  themselves 
intelligible  to  each  other  must  also  have  been  the  most  excitable,  and  in 
them  the  motor  ideas  must  have  been  very  active.  The  word  and  the 
language  of  a  people,  superhuman  gifts,  according  to  the  ancients,  are 
produced  by  reflex  movements,  gestures,  and  interjections.  Even  now 
artists  still  feel  more  keenly  than  others  the  intimate  relation  between 
muscular  movements  and  psychic  functions  ;  they  have  the  gift  of  repre- 
senting the  effects  of  the  emotions  upon  bodily  posture  and  of  idealizing 
them. 

The  great,  picturesque  mode  of  representation  of  the  human  body, 
which  was  the  glory  of  the  Renaissance,  had  its  basis  in  this  physiological 
law. 

A  pleiad  of  the  greatest  artists,  who  perceived  the  internal  power  of 
the  emotions,  popularized  the  study  of  bodily  postures  by  representing  in 
sacred  and  profane  creations  the  feelings  that  thrilled  the  soul.  They 
glorified  the  naked  body,  busying  themselves  with  showing  through  the 
study  of  bodily  forms  and  their  movements  the  perfection  and  the  phi- 
losophy of  art. 

We  need  here  neither  to  think  of  the  heroic  figures  of  Michelangelo 
and  their  powerful  musculature,  nor  of  the  pleasing,  feeling,  and  directly 
perceived  figures  of  Botticelli,  nor  yet  of  the  sublimely  sensual,  passion- 
stirred  figures  of  the  Venetian  school,  in  order  to  comprehend  how  in 
works  of  art  the  mind  is  revealed  in  muscular  contractions.  It  suffices 
to  recall  the  sublime  figures  of  Perugino,  the  teacher  of  Raphael,  which 


394  Angela  Mosso : 

compel  us  to  admiration  with  their  expression  of  the  devotion,  the  enthu- 
siasm, and  the  ardor  of  faith.  Everything  here  is  kept  calm ;  in  these 
figures  we  find  nothing  exciting,  the  expression  of  the  face  alone  mirror- 
ing the  mood  which  the  artist  himself  felt  during  the  production. 

In  my  next  lecture  I  will  speak  further  of  the  basic  conditions  of  the 
emotions.     Here,  however,  I  will  close. 

The  nervous  system,  as  you  know,  consists  of  an  intimate  union 
between  sense-surface  and  muscles.  Golgi  and  Cajal,  the  greatest  dis- 
coverers in  the  structure  of  the  nervous  system,  tell  us  now  that  there 
is  no  difference  to  be  found  in  the  cells  of  the  central  organs,  that  there 
is  no  evidence  of  a  morphological  distinction  between  motor  and  sensory 
cells  in  the  brain. 

The  structure  of  the  nervous  cells  is  the  same  ;  the  relations  alone 
are  different.  Probably  there  is  but  one  nervous  substance,  which  is 
active  for  all  functions.  The  immense  number  of  the  brain  cells  is 
easily  explained,  since  the  cells  can  relieve  one  another  and  the  nervous 
activity  go  on  uninterruptedly  from  one  series  of  cells  to  another.  The 
greatest  complication  lies  in  the  life  of  a  single  brain  cell. 

In  this  lecture  I  have  sought  to  show  how  intimately  related  are 
mental  processes  and  movements.  If  we  desired  to  make  a  pedagogical 
application,  we  might  say  that  physical  education  and  gymnastics  serve 
not  only  for  the  development  of  the  muscles,  but  for  that  of  the  brain 
as  well. 


1.  P.  Flechsig.     Die  Leitungsbahnen  im  Gehim  und  Rtickenmark  des  Menschen.     Leip- 
zig, 1896. 

2.  Th.  Kaes.    Ueber  die  markhaltigen  Nervenfasern  in  der  Gehirnrinde  des  Menschen. 
Neurologisches  Centralblatt,  1894,  p.  410. 

3.  H.  Ambronn  und  Held.     Ueber  experimentelle  Reifung  des  Nervenmarks.     Arch,  f. 
Anat.  u.  Entwicklungsges.     Leipzig,  1896,  p.  227. 

4.  A.  Mosso.    Periodische  Athmung  und  Luxusathmung.    Archiv  f .  Anat.  u.  Physiol. 

1886. 

Die  Diagnostik  des  Pulses.     Leipzig,  1879. 

Ueber  den  Kreislauf  des  Blutes  im  menschlichen  Gehim.     Leipzig,  1881. 

5.       Die  Ermiidung.     Leipzig,  1892. 

6.  "W.  P.  Lombard.     Alterations  in  the  Strength  which  occur  during  Fatiguing  Voluntary 
Muscular  Work.    Journal  of  Physiology,  Vol.  XIV.,  1893,  pp.  97-124. 

7.  Lindley,  E.  H.     A  Preliminary  Study  of  Some  of  the  Motor  Phenomena  of  Mental 
Effort.    Amer.  Journ.  Psychol.,  Vol.  VII.,  pp.  491-517. 

8.  D.  Hansemann.      Ueber  das  Gehirn  von  H.  v.  Helmholtz.      Ztschr.  f.  Psychol,  u. 
Physiol,  d.  Sinnesorgane,  1899,  p.  922. 


Psychic  Processes.  395 

9.    H.  V.  Helmholtz.     Physiologische  Optik.,  p.  922. 

10.  Schoii  und  Mosso.    Eine  Beobachbuug  betreffend  den  "Wettstreit  der  Sehf elder.  Arch, 
f.  Ophth.,  Berlin,  1874,  pp.  269-277. 

11.  A.  Mosso.      Ueber  den  Kreislaui  des  Blutes  im   menschlichen   Gehirn.      Leipzig, 
1881,  p.  101. 

12.  A.  Mosso  et  Pellacani.     Sur  les  fonctions  de  la  vessie.     Arch.  ital.  de  Biol.,  Tome 
L,  p.  97. 

13.  Max  Miiller.     Vorlesungen  liber  die  Wissenschaft  der  Sprache.     Leipzig,  1866,  p.  79. 

14.  G.  J.  Romanes.     L'^volution  mentale  chez  les  animaux.     Paris,  1884,  p.  4. 


THE  MECHANISM   OF  THE  EMOTIONS. 

By  Professor  Angelo  Mosso. 


To-DAY  I  may  be  permitted  to  express  my  own  ideas  about  the  mech- 
anism of  the  emotions. 

We  are  sometimes  surprised  by  a  sad  or  a  joyful  piece  of  news.  We 
all  know  what  happens  in  a  state  of  fear  and  distress.  Physiological  phe- 
nomena occur  that  cannot  be  described.  But  when  we  learn  suddenly 
that  the  news  which  has  troubled  us  is  false,  that  our  fear  and  distress 
had  no  foundation,  the  internal  disturbance  does  not  cease,  the  physio- 
logical phenomena  continue  in  the  organism  in  spite  of  all  efforts  of  the 
will  to  suppress  them. 

The  investigation  of  these  processes  has  shown  that  the  seat  of  the 
emotions  lies  in  the  sympathetic  nervous  system. 

Before  we  were  born,  and  for  a  long  time  after  birth,  our  life  was 
entrusted  to  the  activity  of  the  sympathetic  system  and  the  reflex  move- 
ments derived  from  the  spinal  cord.  We  need  not  be  surprised  at  this, 
when  we  reflect  hoAv  great  an  importance  nature  has  attributed  to  the 
vegetative  and  generative  life  processes  in  the  formation  of  the  organism. 

In  decisive  moments  of  life,  when  the  emotions  are  most  violent,  it  is 
just  the  sympathetic  nervous  system  that  comes  into  action.  The  intes- 
tines and  the  smooth  muscular  fibres  contract  in  order  to  raise  the  press- 
ure of  the  blood,  and  to  utilize  the  blood  better  for  the  brain  and  the 
muscles. 

The  first  observations  concerning  this  subject  were  made  by  me  more 
than  twenty  years  ago.  I  was  able  to  see  that  in  sleep  a  contraction  of 
the  blood-vessels  always  takes  place  as  soon  as  the  sense  organs  and  the 
skin  are  stimulated,  even  when  the  stimulation  is  so  weak  that  the  subject 
does  not  wake  up.^  These  changes,  which  result  without  our  knowledge, 
form  one  of  the  most  remarkable  arrangements  which  we  can  observe 

nor, 


Emotions.  397 

among  the  perfections  of  our  organization.  During  the  interruption  of 
consciousness  our  body  does  not  remain  helplessly  exposed  to  the  influ- 
ences of  the  external  world,  or  in  danger  of  becoming  the  prey  of  its  ene- 
mies. Even  in  sleep  a  portion  of  the  nerve  centres  watches  over  the 
operations  of  the  external  world,  and  prepares  in  good  time  the  material 
conditions  for  the  awaking  of  consciousness.  If  we  glance  back  at  the 
unconscious  processes  which  we  saw  take  place  in  sleep  under  external 
influences,  we  shall  see  that  they  are  all  coordinated  in  correspondence 
with  a  final  object ;  they  all  coincide  in  favoring  the  circulation  of  the 
blood  in  the  brain,  and  thereby  making  it  possible  that,  in  case  of  danger, 
the  organ  may  awake  to  full  activity. 

I  do  not  believe  myself  far  from  the  truth  in  maintaining  that  the 
totality  of  the  reflex  movements  to  be  observed  during  sleep  forms  a  real 
defensive  apparatus  for  the  organism. 

Other  investigators  have  since  demonstrated  the  same  thing.  Two 
years  later,  in  1881,  Dr.  Pellacani  and  I  found  that  even  very  weak  sensa- 
tions caused  a  contraction  of  the  bladder. ^  These  facts  had,  in  general, 
been  already  known,  for  these  contractions  have  become  proverbial  in 
connection  with  fear  and  other  emotional  conditions ;  but  no  one  had 
previously  observed  that  this  organ  reacts  with  such  facility  to  all  sense 
impressions  that  its  tonicity  changes  in  consequence  of  attention  and  incon- 
siderable psychic  processes. 

IT. 

The  organs  of  the  abdomen  and  the  pelvic  cavity  are  just  as  sensitive 
to  the  emotions  as  the  heart.  I  have  studied  the  movements  of  the 
abdominal  organs,  the  stomach,  and  the  rectum.  In  the  smallest  emotions 
movements  of  the  intestines  and  stomach  always  occur. 

In  the  movements  of  the  bladder,  we  must  distinguish  between  active 
and  passive,  i.e.  between  such  as  are  peculiar  to  the  bladder  itself,  and 
such  as  are  transferred  to  it  from  the  diaphragm  and  from  the  walls  of 
the  abdomen. 

In  order  to  investigate  with  exactness  these  movements  of  the  bladder 
itself,  I  have  carried  on  experiments  both  on  the  dog  and  on  woman.  I 
shall  first  explain  the  construction  of  the  apparatus  employed,  and  then 
give  an  account  of  the  experiments  performed. 

The  instrument  made  use  of  was  my  plethysmograph,  which  has  the 
advantage  of  maintaining  the  pressure  constant  and  of  registering  the 
slightest  movements  of  contraction  and  relaxation  of  the  bladder. 


398 


Angela  Mosso : 


A  catheter  for  female  use  (Fig.  1)  A  is  in  communication  witli  a 
glass  tube  BO  which,  with  a  rectangular  curve,  sinks  to  the  depth  of  1  or 
2  cm.  below  the  level  ah  of  the  liquid  contained  in  the  large  receptacle,  P. 
This  descending  tube  must  be  put  into  a  perfectly  vertical  position  before 


Fia.  1.  —  Arrangement  of  the  plethysmograph  for  tracing  the  movements  of  the  bladder. 


every  experiment,  and  fixed  firmly  in  that  position  by  the  iron  support 
DE.  The  pressure-screws  at  the  foot  of  the  support  facilitate  this  nec- 
essary arrangement.  A  test-tube  F^  like  those  used  for  chemical  reactions, 
with  very  thin  walls,  and  suspended  by  two  silk  threads  from  a  pulley  6r, 
is  held  in  equilibrium  by  means  of  a  piece  of  lead  H,  which  has  the 
same  weight  as  the  cylinder  F.     To  this  counterpoise  is  fixed  a  pen  for 


Emotions.  399 

tracing  on  a  smoked  cylinder,  or  on  the  continuous  roll  of  a  Ludwig 
kymograph. 

The  cylinder  F  is  suspended  in  such  a  manner  that  it  has  the  vertical 
glass  tube  0  in  perfect  correspondence  to  its  axis  and  so  that  it  can  move 
up  and  down  without  touching  it. 

In  order  to  avoid  the  attraction  of  the  cylinder  by  adhesion  to  the 
tube  running  down  its  axis,  and  the  consequent  development  of  resistance, 
it  is  advisable  to  furnish  the  lower  end  of  the  tube  with  a  little  ring 
of  sealing-wax,  or  of  india-rubber,  cut  from  a  tube  of  corresponding 
diameter. 

The  cylinder  F  is  drawn  up  until  its  bottom  touches  the  lower  end  of 
the  vertical  tube  ;  the  jar  P,  for  the  time  being,  we  suppose  to  be  full 
of  water. 

The  catheter  A  and  the  bladder  of  the  animal  or  human  being  into 
which  it  is  introduced  must  be  on  the  same  level  ah  as  the  liquid  in  the 
large  vessel.  The  true  level  is  easily  found  by  placing  the  plethys- 
mograph  and  the  cylinder  on  which  the  tracing  is  done  on  a  strong  iron 
table,  which  may  be  raised  or  lowered  by  means  of  a  screw  ;  a  photog- 
rapher's table  serves  the  same  purpose. 

The  tube  AIBO  and  part  of  the  cylinder  P  being  filled  with  water, 
the  catheter  is  introduced  into  the  bladder,  and  the  clip  I  opened.  If 
a  contraction  of  the  bladder  takes  place,  a  quantity  of  water  correspond- 
ing to  the  diminution  of  the  capacity  of  the  bladder  will  flow  into  the 
cylinder  F.  The  cylinder  F,  becoming  heavier  through  this  afflux  of 
water,  is  bound  to  sink  into  the  liquid  of  the  jar  below  until  it  has  dis- 
placed a  volume  of  liquid  corresponding  to  the  increase  of  water  received. 
If  a  dilatation  of  the  bladder  takes  place,  a  certain  volume  of  water  will 
flow  into  it,  and  the  cylinder  becoming  lighter  will  rise  to  a  corresponding 
height  above  its  original  level. 

Had  the  walls  of  the  cylinder  neither  volume  nor  weight,  and  were  the 
jar  full  of  water  P  so  wide  that  the  immersion  of  the  cylinder  would  not 
sensibly  alter  the  level  of  the  water  contained,  it  is  clear  that  the  cylinder 
might  rise  or  sink  without  any  change  taking  place  in  the  level  of  the 
water,  either  in  the  cylinder  or  in  the  jar  P.  But  since  the  walls  of  a 
glass  cylinder,  however  thin  they  may  be,  have  nevertheless  a  certain 
weight  and  volume,  the  immersion  of  the  cylinder  in  water  will  cause  a 
loss  of  so  much  of  its  weight  as  would  correspond  to  the  weight  of  a 
cylinder  precisely  similar  with  walls  of  water.     This  diminution  of  weight 


400  Angela  Mosso  : 

at  the  side  F  oi  &  system  FIT,  which  is  held  in  equilibrium  by  means  of 
the  pulley  G,  must  produce  a  displacement.  The  counterpoise  H,  which 
has  remained  constant,  will  repair  the  loss  in  weight  of  the  cylinder  F  in 
raising  above  the  level  ab  a  weight  of  water  in  the  cylinder  which  will 
equal  the  loss  in  weight  of  the  cylinder  in  its  immersion. 

A  column  of  water  being  raised  in  this  manner  above  the  level  a6, 
there  is  of  necessity  an  augmentation  of  pressure  within  the  bladder  cor- 
responding to  the  height  of  the  column.  In  order  to  remedy  this  defect, 
which  as  a  rule  is  not  more  than  a  column  of  2  cm.  of  water,  we  fill  the 
jar  P  with  a  liquid  which  is  less  dense  than  water,  that  is,  with  alcohol 
and  water.  At  every  contraction  of  the  bladder  a  corresponding  quan- 
tity of  water  will  pass  into  the  cylinder,  and  the  latter  will  sink  into  the 
diluted  alcohol  in  the  jar  P.  As,  however,  the  density  of  this  liquid  is 
less  than  that  of  water,  the  cylinder  F  will  not  only,  in  its  descent,  dis- 
place a  volume  of  alcohol  equal  to  that  of  the  water  which  it  contains,  but 
will  tend  to  sink  lower,  thus  carrying  the  level  of  the  water  it  contains 
below  the  level  ab  of  the  surrounding  alcohol. 

Then,  again,  we  have  already  noticed  that  the  cylinder  in  plunging 
into  the  liquid  loses  gradually  in  weight,  in  accordance  with  the  well- 
known  principle  of  Archimedes,  and  that  the  counterpoise,  which  remains 
constant,  seeks  to  repair  this  loss  by  raising  the  inner  level  of  the  water 
ab  above  the  level  of  the  surrounding  alcohol,  until  the  equilibrium  is 
reestablished. 

We  have,  therefore,  in  this  case  two  forces  acting  in  opposition  :  that 
is,  gravity,  which  tends  to  bring  the  water  level  below  the  alcohol  level 
ab,  and  the  loss  in  weight  undergone  by  the  cylinder  F  during  immersion, 
which  gives  it  an  upward  impetus.  If  these  two  forces  are  equal  they 
will  cancel  each  other  and  the  cylinder  F  will  be  able  to  rise  and  fall  to 
the  extent  of  its  entire  length,  the  level  ab  of  the  water  contained  in  it 
remaining  meanwhile  unaltered. 

In  order  to  obtain  the  exact  degree  of  density  necessary  to  this  end  we 
make  use  of  an  empirical  method ;  that  is,  we  prepare  a  mixture  of  water 
and  absolute  alcohol  if  the  cylinder  has  thickish  walls.  The  liquid  will 
have  the  required  degree  of  density  when  the  cylinder  is  tilled  to  the 
top  with  water  or  empty ;  in  other  words,  when  the  cylinder  is  immersed 
up  to  its  neck  in  the  liquid  or  has  its  base  merely  touched  by  it,  the  level 
ab  of  the  water  contained  in  it  remains  constant  on  the  plane  ab  of  the 
surrounding  liquid. 


Emotions.  401 

For  all  these  necessary  operations  of  filling,  emptying  the  cylinder, 
adding  or  taking  away  water  from  the  bladder,  a  glass  tube  L  graduated 
in  cubic  centimetres  is  made  use  of.  This  tube  communicates  by  means 
of  another  of  india-rubber  closed  by  a  clip  K  and  of  a  T-tube  with  the 
horizontal  tube  BO.  In  order  to  empty  the  cylinder  F  or  take  water  from 
the  bladder,  an  inward  breath  is  drawn  at  the  mouth  of  the  tube  iV,  the 
tube  L  meanwhile  being  closed  with  the  stopper  M,  which  has  a  glass 
tube  running  through  it ;  in  order  to  add  water,  one  need  only  open  the 
nipper  K. 

For  the  experiments  explained  in  the  sequel  a  graduated  and  calibrated 
cylinder  which  contained  30  cc.  to  18  cm.  length  was  made  use  of,  therefore 
every  centimetre  measured  on  the  ordinates  of  our  tracings  corresponds 
to  a  little  less  than  2  cc. 

Care  must  be  taken  that  the  pulley  G-  be  sensitive  enough  and  so  well 
balanced  that  it  remains  in  equilibrium  in  every  position.  A  description 
of  the  apparatus  that  puts  the  cylinder  S  in  movement,  its  velocity  being 
constant  or  variable  as  required,  is  here  unnecessary,  as  it  is  a  piece  of 
clockwork  with  a  Foucault  regulator  which  is  to  be  found  in  all  labora- 
tories. 

When  a  certain  pressure  was  to  be  exercised  on  the  bladder  in  order 
to  dilate  it,  it  sufficed  to  raise  the  table  on  which  the  plethysmograph 
stood,  so  that  the  level  ah  was  above  the  plane  of  the  bladder,  and  to  add 
water  with  the  tube  L  or  to  lower  the  animal  or  human  being. 

In  order  to  measure  exactly  the  pressure  exercised  on  the  bladder 
during  our  experiments,  we  made  use  of  a  water  level  consisting  of  a 
simple  india-rubber  tube  with  an  inner  diameter  of  5  mm.,  1  m.  in  length, 
which  had  at  its  end  two  pointed  glass  tubes  about  20  cm.  in  length.  One 
of  these  tubes  being  placed  near  the  symphysis  pubis,  the  other  was  put 
against  the  jar  P,  and  the  difference  of  level  between  the  bladder  and  the 
plane  ah  was  read  on  a  double  decimetre  measure.  This  height  is  the 
pressure  exercised  on  the  bladder. 

Six  days  after  a  fistula  had  been  applied  to  a  male  dog  the  bladder 
was  connected  through  it  with  my  plethysmograph,  and  the  curve  thus 
obtained  recorded  on  a  rotating  cylinder.  Simultaneously  I  had  the  tho- 
racic and  the  abdominal  respiration  registered.  The  movements  of  the 
bladder  and  of  the  abdomen  are  by  this  means  directly  fixed  upon  the 
cylinder,  while  the  thoracic  respiration  is  represented  reversed  upon  it, 
i.e.  a  sinking  of  the  curve  corresponds  in  the  latter  case  to  expiration,  a 
2i> 


402 


Angelo  Mosso : 


rise  to  inspiration.  Since  the  three  curves  were  recorded  exactly  over 
each  other,  the  movements  could  be  studied  independently  and  com- 
pared (Fig.  2). 

The  curve  for  the  bladder  showed,  as  was  to  be  expected,  also  the 
respiratory  movements.  In  this  curve  we  see  that  the  bladder  begins 
to  contract  before  the  abdomen  rises.  This  comes  from  the  fact  that 
the  sinking  of  the  diaphragm  depresses  the  intestines,  and,  with  them, 
also  the  bladder.  The  effect  must  first  appear  in  the  very  place  where 
the  resistance  is  least,  i.e.  in  the  open  bladder  ;    then  the  abdominal  walls 


Fig.  2. — Relation  between  the  respiratory  movement  of  the  thorax  (line  T)  and  of  the 
abdomen  (line  A)  vrith  the  passive  movements  of  the  bladder  (line  B) . 


are  forced  forward.  Some  time  after  the  contraction  of  the  diaphragm 
the  expansion  of  the  chest  begins. 

But,  besides  these  respiratory  movements,  there  can  be  perceived  in 
the  bladder  curve  a  slight  sinking,  and,  after  it,  again  a  rising  of  the 
whole  curve.  These  are  active  movements  proper  to  the  bladder  itself. 
They  are  easily  distinguished  from  the  passive  movements,  since  they 
occur  less  quickly. 

Another  day  while  we  were  recording  the  movements  of  the  bladder, 
a  servant,  to  whom  the  dog  was  much  attached,  entered  the  laboratory. 
Immediately  the  curve  showed  an  active  contraction  of  the  bladder,  as 
may  be  seen  in  Fig.  3  at  Cr.     In  dbc  we  see  passive  movements  of  the 


Emotions. 


403 


bladder,  which  have  become  weaker  because  the  respiration  is 
more  superficial. 

When,  shortly  before,  another  person,  whom  the  dog  did 
not  know  so  well,  had  entered  the  room,  we  had  also  noticed 
another,  but  stronger,  contraction  of  the  bladder.  In  order 
to  keep  the  dog  quiet,  one  of  us  laid  his  hand  on  his  head. 
(See  P  in  the  curve  of  Fig.  3.)  When  the  hand  was  taken 
away,  and  the  servant  laid  his  upon  the  dog,  there  occurred 
again  an  active,  but  less  marked,  contraction  of  the  bladder. 
As  soon  as  the  respiration  became  more  superficial,  the  passive 
movements  of  the  bladder  became  also  less  distinct. 

After  these  observations,  the  dog  lay  with  eyes  half-closed, 
as  if  he  was  about  to  go  to  sleep.  His  tail  was  touched,  and 
immediately  afterward  the  curve  showed  an  active  contrac- 
tion of  the  bladder,  while  —  what  is  noteworthy—  the  rhythm 
and  depth  of  the  respiratory  movements  did  not  change. 
After  the  bladder  had  again  assumed  its  full  volume,  and 
while  the  dog  was  perfectly  quiet,  his  skin  was  touched,  and 
the  curve  record  showed  at  once  a  stronger,  active  contraction 
of  the  bladder.  In  like  manner,  sensations  of  pain,  which  we 
produced  by  pulling  the  dog's  ears,  caused  strong,  active  con- 
tractions of  the  bladder. 

Such  experiments  were  many  times  repeated.  They  were 
also  carried  on  with  bitches,  the  bladder  being  directly  con- 
nected with  the  plethysmograph  by  the  introduction  of  a  cathe- 
ter, without  previous  establishment  of  a  fistula.  The  results 
which  we  obtained  were  always  the  same.  It  was  sufficient 
to  speak  kindly  to  the  animals,  or  to  caress  them,  to  make  the 
curve  express  the  psychic  influence  upon  their  active  move- 
ments. 

But  I  could  not  rest  content  with  these  results  obtained 
from  animals.  I  needed  to  corroborate  them  by  experiments 
on  human  beings.  Naturally  this  can  be  done  better  with 
woman,  since  with  her  the  bladder  can  be  easily  brought  into 
connection  with  the  plethysmograph  by  the  introduction  of  a 
catheter.  My  clinical  colleagues  were  kind  enough  to  place 
at  my  disposal  some  girls  from  the  hospitals,  who  readily 
offered  themselves  for  the  purposes  of  these  experiments. 


404 


Angelo  Mosso : 


I  may  be  permitted  to  give  an  account  of  these  experiments  also. 

These  experiments  were  carried  on,  otherwise,  as  the  first.  Again  I 
had  the  thoracic  and  abdominal  respiration  and  the  move- 
ments of  the  bladder  independently  recorded.  The  subject 
lay  comfortably  on  a  bed.  Here,  in  a  state  of  complete 
rest,  the  whole  curve  of  the  bladder  was,  at  times,  horizon- 
tal, showing,  at  others,  slight  active  undulations.  To 
touch  the  hand  of  the  subject  lightly  sufficed,  however,  to 
produce  at  once  an  active  contraction  of  the  bladder. 
(See  ^in  the  curve  of  Fig.  4.) 

While  the  subject  was  lying  quietly  on  the  bed,  the 
clockwork  of  the  kymograph  was  wound  up  (see  0).  The 
noise  resulting  was  entirely  unknown  to  the  subject,  but 
the  impression  sufficed  to  cause  itself  to  be  reflected  in 
the  bladder,  and  to  induce  a  contraction,  visible  in  the 
curve.  When  the  subject  was  addressed  (see  P),  it  could 
be  seen  that  the  bladder  contracted  immediately,  while,  if 
she  herself  spoke  (see  i2),  a  series  of  such  contractions 
took  place.  All  these  contractions  are  movements  proper 
to  the  bladder.  As  was  shown  by  other  experiments  as 
well,  they  were  not  transferred  to  the  bladder  from  the 
abdominal  walls  or  from  the  diaphragm,  and  were  not, 
therefore,  passive  movements  F.  The  lower  line  T  marks 
the  seconds. 

I  w^as  particularly  interested  in  the  movements  pro- 
duced in  the  bladder  by  purely  psychic  influences.  These 
are  shown,  e.g.,  by  the  followdng  experiment.  While  the 
girl  lay  quietly  on  the  bed,  and  respiration  was  quiet  and 
normal,  —  this  is  always  showoi  by  the  curves,  —  some  one 
said  to  her,  "Now  I'm  going  to  pinch  you,"  but  without 
doing  so.  Immediately  the  bladder  contracted,  without 
the  slightest  change  being  noticed  in  the  thoracic  and 
abdominal  respiration.  After  rest  had  been  again  restored, 
a  jest  was  spoken  to  the  girl,  and  again  we  perceived  a 
contraction  of  the  bladder  on  the  curve,  without  seeing  any 
modification  whatever  of  the  two  respiratory  curves. 

Beyond  all  doubt,  then,  the  contractions  of   the  bladder  which  we 
observed  were  movements  proper  to  that  organ  itself. 


Emotions. 


405 


All  these  phenomena  may  be  considered  the  most  delicate  reflex  move- 
ments which  occur  in  the  organism.  I  was  particularly  interested  to  know 
what  influence  a  direct  activity  of  the  brain  would  exercise 
upon  the  movements  of  the  bladder,  and  I  carried  on  experi- 
ments to  that  end.  The  subject  had  only  a  slight  education; 
she  was  especially  a  bad  mental  arithmetician,  very  easy 
problems  in  arithmetic  causing  her  difliculties.  She  needed, 
therefore,  in  such  work  to  exert  her  brain  very  much. 

While  she  lay  quietly  on  the  bed  and  her  respiration  was 
quite  normal,  she  was  given  the  following  example  in  arith- 
metic :  "  How  many  eggs  are  seven  dozen  ?  "  Immediately 
the  bladder  was  seen  to  contract  (Fig.  5).  After  this  prob- 
lem was  solved  (see  TT),  we  had  her  multiply  in  her  head 
thirteen  by  twelve,  and  then  a  relaxation  of  the  bladder  was 
to  be  seen. 

I  noticed,  also,  that  merely  speaking  to  the  girl,  without 

her  answering,  was  sufficient  to  produce  a  contraction  of  the 

bladder. 

in. 

The  preponderating  activity  of  the  sympathetic  system 
in  the  emotions  is  so  great  that  the  brain  effort  is  not  able 
to  suppress  it.  Many  men  feel  a  contraction  in  the  abdomen 
when  they  look  down  from  a  tower  or  other  high  place. 
These  troublesome  sensations,  which  are  connected  with  the 
idea  of  a  possible  fall,  are  simply  caused  by  the  contraction 
of  the  bladder  and  the  intestines. 

When  we  investigate,  by  means  of  the  plethysmograph, 
the  movements  of  the  intestines  during  emotional  states,  we 
obtain  the  same  curves  as  we  receive  from  the  movements 
of  the  blood-vessels  of  the  extremities  or  of  the  brain,  or 
from  the  movements  of  the  bladder.  All  these  facts  ena- 
ble us  to  understand  the  mechanism  of  the  emotions  better. 
Emotio  signifies  movement.  We  understand  now  that  the 
constant  and  fundamental  movements  taking  place  in  emo- 
tions are  the  movements  of  the  internal  organs  of  vegetative 
life. 

The  investigations  carried  on  in  my  laboratory  by  Dr.  Kiesow  have 
convinced  me  that  in  certain  emotions  the  blood  pressure  increases,  and 


406  Angela  Mas  so  : 

the  blood-vessels  and  smooth  muscular  fibres  contract  in  order  to  prevent 
the  blood  from  being  dammed  up  in  the  abdominal  cavity. 

In  order  to  increase  the  circulation  of  the  blood  in  the  brain  and  muscles 
our  bodily  machine  has  to  work  under  a  higher  blood  pressure.  This  end 
could  be  attained  only  through  the  sympathetic  system,  which  sends  its 
fibres  every  where  to  the  smooth  musculature.  During  blushing  a  paling 
of  the  skin  can  be  noticed  before  the  blood-vessels  expand,  and  the  blush 
proper  takes  place. 

In  the  study  of  the  emotions  the  reflex  movements  of  the  striped  mus- 
culature of  the  face,  the  extremities,  and  the  trunk  are  of  secondary  signifi- 
cance to  the  physiologist.  They  are  simply  accompanying  phenomena 
and,  just  because  they  are  more  complicated,  less  fundamental. 

However  useful  the  first  reactions  of  the  nervous  system  are,  yet  we 
all  know  that  they  do  not  suffice  for  the  defence  of  the  organism  in 
strong  emotions.  The  nerve  substance  is  so  irritable  that  a  small  shock 
is  enough  to  disturb  the  equilibrium.  I  will  not  enter  into  detail  here, 
since  I  have  already  shown  in  my  book  on  "  Fear,"  how  unstable  is  the 
equilibrium  of  the  nervous  system,  and  how  easily  the  brain  and  the 
sympathetic  system  go  beyond  the  proper  measure  in  their  activity  when 
danger  threatens,  and  existence  is  at  stake. 

Even  a  practiced  observer  is  often  unable  to  decide  from  the  gestures 
and  facial  expression  of  an  individual  whether  he  is  enraged  or  in  a  state 
of  the  greatest  joy. 

To  recall  the  expressions  of  two  so  opposite  emotional  conditions 
sufiices  to  convince  us  that  the  reflex  phenomena  accompanying  them  are 
not  only  useless,  but  even  injurious.  Indeed,  in  great  pain  and  great 
pleasure  we  have  the  same  phenomena :  trembling  of  the  muscles,  secre- 
tion of  tears,  expansion  of  the  pupils,  decrease  of  visual  acuity,  buzzing 
in  the  ears,  oppression  of  the  breathing,  palpitation  of  the  heart,  inability 
to  speak,  exclamations,  convulsive  movements  of  the  diaphragm,  etc.  All 
these  phenomena  are  injurious.  After  the  emotion  is  over  we  feel  nervous 
fatigue,  have  headache,  and  suffer  from  insomnia.  I  am  sorry  to  find  my- 
self in  this  matter  in  disagreement  with  Darwin,  but  I  cannot  concede  that 
the  unconscious  processes  occurring  during  the  emotions  (at  least  the  best 
known  and  most  characteristic)  have  always  a  physiological  purpose. 

If  we  compare  the  expressions  of  pleasure  and  satisfaction  in  their  high- 
est degrees  with  those  of  pain,  it  will  be  seen  that  there  is  one  and  the  same 
mechanism  for  both.      In  my  book  on  "  Fear  "  I  have  shown  that  it  is  the 


Emotions.  407 

quantity  and  not  the  quality  of  the  excitation  which  disturbs  the  equilibrium 
of  our  organism.  Only  the  processes  which  take  place  in  the  system  of  the 
great  sympathetic  are  purposive  and  advantageous  for  the  preservation  of 
life.  And  it  cannot  be  otherwise.  The  animals,  whose  involuntary  move- 
ments preserved  them  from  destruction  in  danger,  won  in  the  struggle  for 
existence  over  others  who  possessed  in  less  marked  degree  this  capacity. 

Whatever  the  emotions  may  be,  we  always  see  that  in  these  states  the 
blood  pressure  increases,  the  heart  beats  become  stronger,  and  the  respira- 
tion deeper.  These  advantageous  effects  are  the  same  in  man  as  in  ani- 
mals, when  they  fix  the  attention,  are  passionately  excited,  curious  or 
jealous,  or  when  they  run  at  play  or  in  pursuit  of  prey. 

But  as  soon  as  the  emotion  becomes  more  intense,  the  equilibrium  of 
the  organs  ceases.  The  condition  of  excitability  is  increased  and  becomes 
more  complicated,  contractions  of  the  muscles  and  changes  in  the  sense 
organs  take  place,  from  which  it  results  that  the  capacity  for  resistance  of 
the  organism  is  lowered.  In  strong  emotions,  as  in  rage  and  anger,  we 
are  overpowered  by  unconscious  and  discoordinated  movements,  and  a 
penetrative  and  irresistible  transformation  occurs  in  us,  as  if  the  influ- 
ence of  education  had  been  extinguished,  as  if  our  reason  had  suffered  an 
eclipse.  We  are  no  longer  able  to  suppress  the  internal  excitement,  the 
voice  refuses  its  office,  and  we  utter  a  wild  cry.  Many  persons  in  such 
states  gnash  their  teeth  like  wild  beasts,  others  act  foolishly,  like  children. 

These  disturbances  occur  not  only  in  the  reflex  movements,  but  also 
in  the  conscious  processes,  and  more  even  in  the  latter  than  in  the  former. 
Education  has  taught  us  that  we  must  seek  to  master  and  to  calm  our- 
selves during  this  internal  excitement,  for  in  these  states  we  lack  mental 
clearness  and  power  of  judgment,  and  consciousness  cannot  again  regain 
control  until  these  discoordinated  reflex  movements  have  ceased.  Even  the 
ancients  knew  that  strong  emotions  resembled  a  suddenly  occurring  sick- 
ness. The  legend  of  ancient  Rome  idealized  a  king  in  order  to  represent 
war.  They  gave  him  the  name  Hostilius,  which  is  derived  from  hostis. 
Tradition  further  informs  us  that  this  king  erected  a  temple  to  "  Pallor  and 
Fear,"  for  pallor  and  fear  were  looked  upon  as  malevolent,  destructive 
deities  who  must  be  appeased  in  order  that  the  soldiers  might  be  victorious 
in  battle.^  . 

1.  A.  Mosso.    Ueber  den  Kreislauf  des  Blutes  im  menschlichen  Gehirne.     Leipzig,  1881. 

2.  A.  Mosso  e  Pellacani.    Sulle  funzioni  dellavescia.    Mem.  d.  R.  Accad.  dei  Lincei,  1881. 

3.  E.  Pais.    Storia  di  Roma.     Torino,  1898.     Vol.  I.,  Parte  I.,  p.  305. 


I 


I 


410  August  For  el: 

that  is,  the  neurone,  the  cell  with  its  fibre  and  branched  processes.  When, 
in  1886-87,  about  the  same  time  as  His,  I  first  put  forth  this  view  as 
a  probable  hypothesis  on  the  ground  of  numerous  facts,  I  had  no  idea 
that  tliree  years  later  my  illustrious  colleague,  S.  Ramon  y  Cajal,  would 
establish  the  matter  histologically  in  such  a  beautiful  and  conclusive 
manner.  The  nerve  elements  do  not  anastomose,  as  was  formerly  be- 
lieved, but  touch  one  another  by  ramifying  branches,  end-baskets,  arbor- 
izations, etc.  Every  nerve  fibre  (axone),  together  with  its  ramifications, 
is  merely  a  part  of  the  protoplasm  of  a  certain  cell.  Further,  Schiller 
showed  in  my  laboratory  that  the  number  of  nerve  elements  in  the  new- 
born (oculomotor  nerve  of  the  cat)  was  approximately  as  large  as  in 
the  adult,  and  that  only  the  caliber  of  the  medullary  fibres  differed 
enormously.  Since  it  appears  certain  that,  in  a  lifetime,  destroyed  ele- 
ments of  the  central  nervous  system  are  never  replaced  by  newly  formed 
ones,  we  may  draw  the  conclusion  that  the  nerve  elements  of  an  old 
person  are  the  same  as  those  of  his  childhood,  a  point  very  important 
for  the  theory  of  memory. 

A  matter  of  further  importance  is  the  relation  of  chromatic 
reaction  of  the  nerve  cell,  established  by  Nissl,  to  the  details  of  its 
finer  structure.  The  fibrils,  already  recognized  by  v.  Kupffer,  Schultze, 
Leydig,  and  others,  and  the  chromatic  bodies  present,  as  it  were,  ele- 
ments of  a  second  order,  which  increase  considerably  the  complication 
of  nerve  structure  and  open  new  perspectives.  The  same  holds  for  the 
change  of  cell  structure  after  exhausting  activity,  demonstrated  first  by 
Dr.  Hodge  of  this  University,  and  for  the  grave  changes  due  to  the 
use  of  alcoholic  beverages  established  by  many  investigators  —  an  addi- 
tional reason  why  we  should  banish  those  abominable  social  and  indi- 
vidual nerve  poisons  from  human  diet. 

Hand  in  hand  with  the  progress  mentioned,  we  notice  the  advances 
in  the  recognition  of  local  structural  conditions  in  the  brain  of  man 
and  animals,  of  systems  of  neurones,  etc.,  especially  through  v.  Gud- 
den's  method  of  experimental  atrophy;  but  also  by  direct  anatomical 
study.  The  works  of  Dejerine  and  Mme.  Dejerine-Klumpke,  and  of 
Kolliker,  are  encyclopaedic  monuments  of  those  researches.  I  mention 
further  the  doctrine  of  localization  built  up  by  Broca,  Hitzig,  Ferrier, 
Munk,  etc.,  which  can  only  lead  slowly  to  a  clear  and  objective  under- 
standing of  the  whole  in  connection  with  an  accurate  knowledge  of  anat- 
omy, of  pathology,  and  of  the  experimental  method  of  v.  Gudden.     At 


Hypnotism.  411 

the  same  time,  we  must  always  guard  ourselves  against  speculations  built 
on  insufficient  and  unsafe  ground,  such  as  the  recent  doctrines  of 
Flechsig.  While  it  is  possible  to  establish,  to  a  great  extent,  the  func- 
tion of  the  peripheral  nerves  and  their  nuclei  of  origin  by  direct 
observation  and  experiment,  and  while  we  have  also  a  certain  direct 
access  to  the  study  of  the  spinal  cord,  we  recognize  the  function  of 
the  cerebral  cortex  in  two  ways  :  (a)  by  physiological  experiments  and 
investigations:  (5)  by  so-called  introspective  or  psychological  observa- 
tion and  experiments.  But  the  mutual  relations  of  sensory  stimulation 
and  muscular  action  to  the  hemispheres  must  also  be  observed  both 
psychologically  and  physiologically.  If  I  prick  some  one,  the  subse- 
quent reflex  contraction  is  observed  by  me  physiologically ;  whereas 
the  character  and  intensity  of  the  pain  which  the  person  claims  to  feel 
can  only  be  measured  by  him  on  the  psychological  side.  I  see  and  hear 
his  answers  physiologically  only,  but  make  out  their  sense  psycho- 
logically only,  etc. 

If  we  consider  more  accurately  this  continual  interaction  between 
psychological  and  physiological  phenomena  in  the  light  of  our  knowl- 
edge of  the  brain,  we  are  bound  to  become  sure  of  one  thing,  viz. 
that  there  is  a  dark  field  between  the  subjectively  accessible,  psycho- 
logical, sentient,  and  perceptive  parts  of  the  hemisphere  cortex,  and 
those  representing  the  physiologically  accessible,  sensory  receiving  sta- 
tions and  the  motor,  or  efferent,  mechanisms  of  motion.  In  this  dark, 
intermediate  field,  powerful  accumulations  of  stimuli  of  an  unconscious 
nature  must  go  on,  and  obscure,  instinctive  automatic  mechanisms, 
inherited  from  our  animal  ancestors,  must  work  and  influence  us  un- 
consciously to  a  great  extent  in  the  shape  of  impulses  and  feelings. 
We  are  driven  to  assume  that  the  great  ganglionic  nerve  centres  of 
the  base  of  the  brain,  corpora  striata,  thalami,  pons,  tegmentum,  cere- 
bellum, must  play  a  part  utterly  obscure,  which  perhaps  might  clear 
up  many  points,  if  we  could  penetrate  more  deeply.  Unfortunately 
this  point  is  still  far  from  accessible,  since  the  fragments  furnished  by 
physiology  are  hardly  fit  to  be  digested. 

We  should  not  forget  in  this  whole  question  what  recent  investiga- 
tions have  demonstrated,  viz.  that  the  field  of  expansion  of  a  single 
nerve  element,  a  neurone,  may  be  very  large.  Just  think  of  a  Betz- 
cell  of  the  central  convolutions,  the  nerve  process  of  which  reaches 
through  the  corona  radiata,  the  crus,  pons,  and  pyramid,  as  far  as  the 


412  August  For  el: 

spinal  cord,  or  of  a  cell  of  the  anterior  horn  of  the  lumlDar  cord, 
whose  process  reaches  muscles  of  the  foot.  Thus,  neurones  of  varied 
significance  and  destination  cross  and  interweave  in  a  thousand  ways 
in  the  central  and  in  the  peripheral  nervous  systems,  in  order  to  form 
the  wonderful  machinery.  One  sees,  from  this  alone,  how  brutal  and 
defective  the  physiological  experiments  in  the  brain  must  be,  and  how 
indefinite  the  physiological  concept  of  a  "  centre "  is. 

Physiological  Remarks. 

There  is  but  little  in  the  old  nerve  physiology  that  can  be  used 
to-day,  because  it  rested,  to  a  great  extent,  on  erroneous  histological 
concepts.  We  must  accept  the  well-known  fundamental  facts  concern- 
ing stimulation,  inhibition,  reflexes,  etc.,  and  also  the  results  of  the 
pioneers  of  brain  physiology,  Flourens,  Magendie,  Vulpian,  Duchenne, 
etc.  We  may  conceive  that  the  brain  is  a  powerful  accumulator,  a  kind 
of  very  highly  complicated  dynamo,  in  which  a  still  enigmatical  physico- 
chemical  wave-like  power  prevails,  for  which  I  have  used  the  expression 
"neurokyme,"  (the  "force  neurique  "  of  the  French).  This  force  does 
not  cause  any  motion  of  the  masses,  and  consequently  belongs  to  the  type 
of  molecular  motion,  or  vibration,  as  is  shown  by  its  great  velocity  of 
conduction.  Its  action  leaves  in  the  cell  visual  changes  in  the  form 
of  material  signs  of  exhaustion.  It  may  be  accumulated  as  energy  by 
so-called  mechanisms  of  inhibition,  and  again  be  discharged  in  definite 
channels  by  what  Exner  calls  "Bahnung."  In  this  connection,  O.  Vogt 
has  justly  insisted  on  the  important  fact  that  in  excessive  stimulation 
the  effect  is  often  suddenly  stopped  because  a  radiation  of  neighboring 
centres  of  neurones  takes  place,  which  is  apt  to  lead  away  the  entire 
neurokyme,  if  those  centres  are  more  easily  excitable.  In  this  way  it  is 
in  a  manner  possible  to  understand  associative  activity.  To  enter  upon 
detail  would  lead  too  far ;  but  I  beg  to  say,  in  a  general  way,  that  it  is 
well  known  that  certain  functions  become  much  easier  and  stronger  after 
a  while  through  practice ;  whereas,  in  an  obscure  but  very  frequent 
manner,  on  the  other  hand,  certain  single  impulses  may  leave  behind 
lasting  inhibitions,  or  stimuli,  and  perhaps  disorders  of  function  which 
may  take  a  pathological  character,  and  seriously  tantalize  the  victim. 
Such  points  were  used,  a  few  years  ago,  by  Breuer  and  Freud  in 
Vienna,  for  the  foundation  of  their  doctrine  of  arrested  emotions,  which, 


Hypnotism.  413 

unfortunately,  was  developed  into  a  one-sided  system,  although  it  started 
from  correct  facts.  Thus  especially  violent  affects  are  apt  to  leave  be- 
hind all  sorts  of  nervous  disorders  (convulsions,  paralysis,  pains,  dyspep- 
sia, menstrual  disorders).  Breuer  and  Freud  tried  to  lead  the  patients 
in  a  hypnotic  condition  to  the  causative,  frequently  forgotten,  and  fre- 
quently sexual  moment  of  the  trouble,  to  make  them  dream  over  that 
moment  and  to  give,  once  and  forever,  a  counter  suggestion,  curing  the 
disorder.     In  many  cases  this  works  ;  but  by  no  means  always. 

Before  all,  we  must  acknowledge  with  Isidore  Steiner  that  the 
greatest  nerve  centre  has  the  dominant  position  in  this  interaction  of 
the  neurokymes,  owing  to  its  greater  mass.  It  becomes  the  guide  and 
director  of  the  whole,  and  the  activity  of  the  other  centres  is  brought 
into  subjection.  Steiner  proved  this  by  a  clever  experiment  on  a  fish, 
and  showed  that  in  those  animals  the  mid-brain,  and  not  the  fore-brain, 
is  the  director  and  the  soul  of  the  animal  ;  consequently  it  is  not  the 
morphological  homology  which  decides  the  absolute  anatomical  size  or 
physiological  strength,  and  hence  the  eminently  important  fact  that  the 
relative  size  of  the  individual  part  of  the  central  nervous  system  is  of 
great  importance  for  the  relative  independence  or  dependence.  We  see 
the  proof  for  this  fact  in  the  comparative  physiology  of  the  animal  series. 
The  spinal  cord  and  ganglia  are  far  more  independent  in  the  lizard  than 
in  the  rabbit ;  much  more  independent  in  the  latter  than  in  the  dog ;  and 
in  the  dog,  much  more  independent  than  in  man.  In  man  these  organs 
have  become  the  subordinated  servants  of  the  hemispheres  and  totally 
dependent,  although  their  structure  is  much  more  complicated  than  in 
the  lizard. 

We  need  not  wonder,  therefore,  if  the  function  of  these  lower  centres 
is  governed  and  influenced  most  powerfully  by  the  dynamics  of  the  fore- 
brain  just  named,  even  when,  as  in  the  sympathetic,  only  loose  connection 
exists,  such  as  would  suggest,  ordinarily,  a  greater  independence. 

How  is  a  neurokyme,  which  spreads  over  an  axone,  transferred  from 
one  neurone  to  the  others  by  the  contact  of  dendritic  ramifications? 
Duval  thinks,  by  an  amceboid  motion  of  the  dendrites,  and  we  read  that 
lately  such  motions  have  been  directly  observed  in  transparent  animals. 
This  hypothesis  seems,  however,  quite  immature  as  yet.  It  does  not 
explain  the  extreme  rapidity  of  the  conduction  of  the  neurokyme.  The 
functional  play  of  the  neurones  is  better  explained  by  pure  molecular 
motion,  as,  for  instance,  in  electricity.     It  would  seem  that  these  hypoth- 


414  August  For  el  : 

eses    are   quite   premature,  and   we   must  wait   for   actual   progress   in 
observations. 

Finally,  we  must  maintain  the  fundamental  fact  of  memory,  conscious 
or  unconscious,  viz.  the  residual  of  a  dynamic  trace  of  every  nerve  activ- 
ity. Such  a  trace  always  facilitates  the  repetition  of  a  corresponding 
activity,  even  if  it  should  be  forgotten  subsequently,  and  the  entire 
activity  may  be  called  forth  again  by  the  effect  of  the  stimulus  merely 
associated  with  the  first  one  ;  for  instance,  ordinary  remembrance.  Or- 
ganic memory  is  independent  of  consciousness  and  is  the  same  for  motor 
as  for  sensory  and  central  activities,  and  even  for  reflexes  and  functions 
of  the  sympathetic. 

Sleep  and  Waking  State  —  Consciousness. 

Man  is  normally  limited  to  two  states  of  his  brain  life  :  sleep  and 
waking  condition.  Physiologically  considered  sleep  means  a  relative 
rest  from  cerebral  activity  with  recuperation  of  the  exhausted  neurones 
by  chemical  sj'^nthesis,  whereas  in  the  waking  state  processes  of  oxidation 
predominate.  This  is  certain  beyond  doubt,  but  to  draw  the  conclusion 
that  sleep  is  called  forth  by  the  formation  of  fatigue  products,  such  as 
lactic  acid,  or  that  sleeplessness  could  be  cured  by  swallowing  lactic  acid, 
as  Preyer  did,  is  to  become  a  victim  of  fallacies. 

It  does  not  take  much  acuteness  of  observation  to  see  that  there  is  a 
form  of  sleep  which  is  not  rest,  and  that  the  brain  can  rest  fairly  well 
even  in  the  waking  state.  Further,  one  may  sleep  much  and  excessively 
though  not  exhausted,  and  again  may  keep  awake  in  a  state  of  cerebral 
exhaustion.  Again,  every  unprejudiced  observer  must  be  struck  with 
the  usually  rather  sudden  qualitative  change  in  the  attitude  of  a  wak- 
ing and  of  a  sleeping  person.  That  sleep  is  readily  called  forth  by 
certain  associations,  regular  hours,  etc.,  is  also  obvious.  Finally,  dreams 
give  us  a  chance  to  look  into  the  life  of  sleep  from  the  psychological 
side. 

All  these  factors  tend  to  present  sleep  as  a  state  of  qualitatively  modi- 
fied cerebral  activity.  This  is,  however,  only  intelligible  in  connection 
with  the  concept  of  consciousness. 

It  was  a  fundamental  mistake  of  practically  all  physicians  and  most 
psychologists,  to  think  of  consciousness  as  a  something,  as  a  form  of  cere- 
bral   activity,  i.e.  to  confuse  the  plastic  concentrative  activity  of    our 


Hypnotism.  415 

attention  with  the  purified  phenomenon  of  subjectiveness.  "We  will  not 
quarrel  over  words.  I,  for  one,  am  satisfied  to  be  able  to  rest  my  view  on 
such  a  psychologist  as  Spencer.  If  any  one  cares  to  use  the  word 
"  consciousness  "  in  any  other  sense,  he  may  do  so  as  long  as  he  gives  us 
another  word  for  that  which  I  understand  to  be  consciousness,  viz.  the 
phenomenon  of  the  inner  reflection  of  the  ego,  the  subjective  side  of  the 
phenomena.  Slight  activities  of  the  brain,  as  well  as  violent  ones,  are 
reflected  by  it  and  become  "  conscious  "  ;  but  equally  violent  activities 
seem  not  to  become  conscious;  they  remain  "unconscious."  Conse- 
quently we  are  forced  to  distinguish  between  a  conscious  and  an  uncon- 
scious life  of  the  brain. 

The  entire  discord  of  the  phenomena  rests  on  the  peculiar  facts  : 
(1)  that  the  activity  of  the  brain  does  not  take  place  in  one  single  conti- 
nuity and  connection,  that,  for  instance,  two  subjective  reflexes  may  occur 
simultaneously  without  being  connected  or  "  associated,"  so  that  the  one 
does  not  know  of  the  other  and  one  is  unconscious  in  reference  to  just 
that  other  reflex  ;  (2)  that  everything  which  is  subjectively  "  forgotten  " 
drops  out  of  the  connection  of  consciousness  so  that  amnesia  and  uncon- 
sciousness are  continually  confused. 

The  resulting  fallacies  are  evident ;  we  always  call  unconscious  such 
actions  or  states  of  the  brain  as  were  conscious  and  appear  to  us  to  be 
forgotten,  or  which  were  illuminated  by  a  consciousness  other  than  our 
ordinary  remembered  consciousness. 

In  order  to  be  concise,  I  venture  to  offer  a  hypothesis  which  agrees 
very  well  with  all  the  facts  :  Every  nerve  activity  is  conscious,  i.e. 
possesses  internal  reflection  ;  but  these  reflections  are  by  no  means  all 
capable  of  remaining  in  a  synthetical  connection  with  one  another. 
For  this  we  need  a  more  intense  associated  activity,  especially  where  the 
connection  is  to  be  fixed  by  memory.  Everything  which  appears  no 
longer,  or  not  at  all,  in  this  connection,  loses  the  subjective  connection 
with  our  memory  ego,  and  we  erroneously  deem  it  unconscious,  whether 
it  be  a  past  or  actual  activity  of  the  hemisphere,  or  only  one  of  the  sym- 
pathetic or  of  the  spinal  cord.  In  order  to  express  such  a  view  consist- 
ently we  must :  — 

a.  Eliminate  the  word  "  unconscious,"  and  replace  it  by  "subconscious  " 
or  "otherwise  conscious." 

h.  Accept  a  multiplicity  of  fields  of  consciousness,  or  consciousnesses, 
the  contents,  i.e.  the  illuminated  cerebral  activities,  of  which  are  physio- 


416  August  For  el: 

logically  connected  and  influence  one  another  subjectively,  according 
to  the  kinds  of  activities  underlying  them  ;  they  are  only  rarely,  or 
partially,  or  never  connected  (associated).  That  subjective  associations 
require  higher  intensity  and  more  synthesis  than  the  objective  (physio- 
logical) ones  has  been  shown  by  psychology  (Hoffding). 

c.  Consider  all  brain  activity  as  completely  independent  of  the  accom- 
panying (subjective)  illuminations  by  consciousness,  whether  it  appears  to 
us  psychological  or  physiological.  This  is  theoretically  possible,  at  least 
for  psychological  phenomena. 

d.  Consider  the  word  "  consciousness  "  as  the  expression  of  an  inner 
aspect  of  life,  not  as  the  name  for  any  special  thing,  an  activity,  a 
peculiarity.  We  use  the  words  "  energy  "  and  "  matter"  in  a  similar  way  ; 
there  is  no  energy  without  matter,  as  little  as  matter  without  energy.  In 
the  same  way  consciousness  in  our  sense  is  nothing  in  itself,  but  merely 
the  subjective  aspect  of  brain  life,  an  aspect  probably  common  to  all  life. 

If  we  adhere  to  what  is  said,  we  find  sleep  intelligible.  We  observe 
the  following  in  the  condition  of  sleep  :  — 

1.  The  cerebral  activity  is  highly  dissociated.  The  ideas  follow  one 
another  in  a  chaos  which  does  not  correspond  any  longer  to  the  connec- 
tion of  things  in  the  actual  world.  Things  which  exclude  one  another  in 
reality  appear  identical,  and  the  reverse.  My  friend  may  be  at  once  a 
dog,  water,  or  a  piece  of  wood.  I  may  be  simultaneously  dead  and  mar- 
ried, or  simultaneously  in  Europe  and  America,  or  see  my  head  before  me 
at  a  distance  of  twenty  yards.  If  you  study  this  dissociation  more  closely, 
you  readily  see  that  it  affects  not  only  the  logical  sequence  of  higher  con- 
cepts, but  the  very  make-up,  even  the  constituents,  of  perceptions.  The 
notion  of  time  and  place,  the  single  (usually  subconscious)  sensations  con- 
stituting a  perception,  are  frequently  disjointed,  and  dance  together  a 
veritable  Walpurgis  dance.  Again,  there  prevail  powerful  inhibitions 
which  prevent  all  orderly  association  and  keep  us  in  an  oppressive  despair 
and  impotence.  The  same  chaos  prevails  in  the  field  of  emotions  and  of 
volitions,  but  here  the  inhibition,  or,  in  the  emotions,  powerful  ebullitions 
predominate. 

2.  The  conceptions  of  dream  life  are  hallucinations.  When  asleep  we 
no  longer  distinguish  between  perception  and  spontaneous  conception. 
The  sensory  stimuli  either  do  not  become  conscious  at  all  or  they  are  alle- 
gorized; on  the  other  hand,  all  perceptions  appear  as  actual  happenings. 
Moreover,  the  concept  of  a  motion  is  usually  not  capable  of  eliciting  the 


Hypnotism.  417 

corresponding  actual  muscular  contraction.  It  is  merely  represented  by 
a  motor  hallucination. 

3.  Since  there  are  no  corrective  concepts,  some  emotions  and  ideas 
may,  in  this  condition,  obtain  an  enormous  power,  overcome  obstacles 
unsurmountable  in  the  waking  condition,  and  hence  produce  especially 
intense  consequences.  Just  think  of  the  evil  after-effects  of  dreams,  of 
nocturnal  pollutions,  etc. 

Duval  has  lately  ventured  to  make  a  new  hypothesis  of  sleep.  He 
believes  that  all  the  terminations  of  the  neurones  are  in  active  contact 
during  the  waking  state  by  some  kind  of  amoeboid  activity.  During 
sleep  he  thinks  they  simply  withdraw,  so  that  the  contact  ceases.  What 
a  beautiful  and  simple  explanation  for  all  the  dissociations  and  elimina- 
tions of  all  the  senses!    For  the  time  being  this  view  is  a  mere  hypothesis. 

Nothing  demonstrates  so  thoroughly  the  deficiencies  of  Weber's  and 
Fechner's  psycho-physical  law  as  sleep.  There  are  too  many  intermediate 
forces  between  the  "  subject  "  and  the  measurable  external  stimuli.  Heer- 
wagen,  for  instance,  tried  to  measure  the  intensity  of  sleep  by  the  inten- 
sity of  a  noise  necessary  to  wake  the  sleeping  person !  These  two  quan- 
tities are  practically  without  any  connection.  Everything  depends  on 
the  kind  of  association.  The  same  sleeping  person  can  be  aroused  by  a 
very  slight  unusual  sound,  while  the  greatest  noise  need  not  disturb  the 
sleep.  Heerwagen  further  tried  to  make  statistics  on  dreams  by  asking 
people  for  them ;  but  he  forgot  that  most  dreams  are  forgotten,  and  that 
the  forgetting  of  dreams  and  the  "  not  dreaming  "  are  two  utterly  differ- 
ent things.  I  am  convinced  that  everybody  dreams  all  the  night  through. 
I,  myself,  if  I  observe  myself  at  all,  cannot  be  aroused  at  any  time  of  the 
night  without  just  having  dreamed. 

Finally,  there  are  all  degrees  of  sleep,  from  the  lightest,  best  asso- 
ciated, to  the  deepest.  The  former  shows  all  transitions  to  the  waking 
state.  The  difference  in  the  cerebral  activity  during  the  sleeping  and  the 
waking  condition  implies  a  corresponding  difference  of  the  contents  of 
consciousness.  We  consequently  have  two  alternating  conscious  states 
every  day  and  every  night,  and  our  ego  is  quite  characteristic  in  each. 
A  good  trustworthy  man  may  become  a  thief,  a  murderer,  and  a  licentious 
person,  a  courageous  man  may  be  cowardly  during  sleep,  etc.  We  usually 
forget  our  dreams  owing  to  the  dissociation,  so  that  our  two  states  of 
consciousness  in  sleeping  and  waking  condition  show  only  a  slight  and 
fragmentary  connection.    Not  infrequently  we  find  somnambulists  who  act 

2b 


418  August  For  el: 

in  a  coordinate  manner  during  sleep.  One  who  did  all  sorts  of  house- 
work in  her  sleep  was  very  tired  after  it,  but  did  not  remember  anything. 
This  is  also  the  rule  in  the  very  frequent  somnambulism  of  children. 
Out  of  such  an  orderly  activity  of  a  sleeping  brain,  i.e.  out  of  the  spon- 
taneous somnambulism,  originates  an  extraordinary  and  especially  instruc- 
tive form  of  double  consciousness,  such  as  has  been  described  by  McNish, 
Azam,  Dessoir,  and  myself. 

In  my  case  (see  Zeitschrift  fiir  Hypnotismus.,  1898),  a  German  made 
an  eight  months'  journey  to  Australia  and  back  without  in  the  least 
remembering  it.  The  amnesia  of  retrograde  and  antegrade  character 
came  on  after  dengue  fever.  Later  I  was  able  to  revive  the  memory  by 
suggestions.  It  was,  however,  impossible  to  establish  a  connected  associ- 
ation between  the  two  visits  to  Melbourne  on  his  journey  out  and  back. 
Those  two  Melbournes  remained  for  him  two  entirely  different  cities. 

The  Data  of  Hypnotism. 

At  all  times  in  the  history  of  mankind,  hypnotism  has  played  a  great 
r61e.  Magicians,  miracles,  miraculous  cures,  sorcerers,  the  fakirs  of 
India,  are  so  many  proofs  of  this.  The  principal  fact  was  always  the 
apparent  and  subsequently  also  actual  power  of  certain  persons  over 
others,  the  ecstatic  catalepsy  or  sleep  produced  by  them,  the  asserted 
prophecies  of  the  hypnotized,  the  cure  of  diseases,  the  miracles,  etc.  A 
magnificent  instance  of  hypnotic  influence  may  be  found  in  the  history  of 
King  Zoroaster  (cf.  StoU's  book  on  this  topic).  In  the  beginning  of  this 
century  Mesmer  thought  to  have  discovered  a  new  natural  law  in  those 
phenomena,  a  new  "  fluid,"  which  he  assumed  to  be  magnetism.  Espe- 
cially in  living  beings  he  called  it  animal  magnetism.  He  produced  hys- 
terical convulsions  usually  by  contact  of  men,  finally  "  magnetized  "  trees 
and  did  other  absurd  things;  but  also  cured  a  number  of  patients.  Con- 
demned by  the  French  Academy  as  an  obvious  fraud,  he  came  to  a  sad  end. 
But  he  retained  adherents.  One  of  them,  Puysegur,  discovered  the  quiet 
hypnotic  sleep.  They  all  adhered  to  the  belief  in  a  mysterious  magnetic 
fluid.  Braid,  an  English  physician,  was  the  first  to  take  a  great  step 
toward  a  scientific  elucidation  of  the  question.  He  found  that  the 
whole  series  of  phenomena  depended  not  on  a  fluidum  coming  from  the 
outside,  but  on  the  brain  and  nervous  system  of  the  person  influenced. 
The  very  title  of  his  book,  "  Neurohypnology,"  shows  this.    He  found  that 


Hypnotism.  419 

certain  stimuli  and  also  certain  ideas  could  produce  this  changed  cerebral 
state,  hypnotism.  By  this  he  had  established  the  principal  fact,  but  he 
made  a  mistake  in  the  method  by  ascribing  a  capital  role  to  the  periph- 
eral stimuli,  just  as  Charcot  did  later  on.  He  hypnotized  with  brill- 
iant objects,  and,  therefore,  did  not  obtain  thoroughgoing  results. 
These  we  owe  to  Liebault,  at  Nancy,  and  to  his  medically  and  philosoph- 
ically highly  educated  friend,  Professor  Bernheim.  The  doctrine  of 
Liebault  and  Bernheim  has  placed  hypnotism  among  the  fields  for  scien- 
tific research,  from  which  it  will  not  disappear  again.  This  doctrine 
reduces  hypnotism  to  the  concept  of  suggestion.  In  this  light  we  shall 
mention  briefly  the  principal  manifestations. 

The  fact  that  in  falling  asleep  or  awaking  the  entire  mode  of  brain 
activity  is  suddenly  altered,  gives  us,  I  believe,  the  key  to  an  under- 
standing of  hypnotism.  Conceive  some  means  by  which  we  are  able  to 
produce  those  two  kinds  of  activity  according  to  our  needs,  and,  more- 
over, to  localize,  —  to  limit  them  to  certain  fields,  —  and  you  see  before 
you  almost  the  entire  series  of  hypnotic  phenomena.  For  this  purpose 
you  should  merely  be  able  to  direct  the  cerebral  activity  of  your  neighbor, 
inhibit  and  facilitate,  associate  and  dissociate.  This  actually  happens 
by  means  of  evoking  certain  concepts,  which  are  known  to  lead  most 
easily  to  dissociation.  A  priori^  this  may  appear  peculiar  and  improbable. 
As  a  matter  of  fact,  it  is  exceedingly  simple  and  common.  All  human 
beings  are  naturally  more  or  less  suggestible  and,  therefore,  hypnotizable, 
although  not  all  are  equally  influenced  by  others.  Everything  that  pro- 
duces the  concept  of  sleep,  everything  that  makes  man  passive,  or  throws 
him  into  ecstas}^  admiration,  or  confidence,  may  be  used  by  the  rapid  and 
concentrated  action  of  the  hypnotizer  to  dissociate,  inhibit,  or  stimulate, 
any  activity  of  his  subject, — it  may  produce  the  desired  and  foretold 
effect,  the  mechanism  of  which  remains  subconscious  in  the  person  influ- 
enced. It  is  especially  advantageous  to  begin  with  such  effects  as  are 
readily  obtained.     This  is  the  principle  of  Liebault's  method. 

For  instance,  I  yawn;  it  becomes  "infectious."  Another  yawns; 
with  him  it  has  the  effect  of  a  suggestive  influence.  He  yawns  because  I 
yawned ;  however,  he  remains  subconscious  of  the  mechanism  which  pro- 
duces the  yawning.  Now,  I  use  the  beginning  dissociation,  and  tell  him 
rapidly  and  with  assurance  :  "  You  are  quite  sleepy,  you  cannot  keep  your 
eyes  open,  you  cannot  open  them,  you  have  a  warm  feeling  in  your  feet ; 
look  at  me ;  you  are  already  asleep,  your  arms  are  heavy,"  etc.    Quite  fre- 


420  August  Forel : 

quently  the  subject  will  feel  and  even  show  the  one  or  the  other  of  these 
phenomena.  If  he  is  very  suggestible,  he  will,  perhaps,  be  asleep  in  a 
few  seconds,  to  the  surprise  of  those  around.  This  sleep  is,  however,  dis- 
tinguished from  ordinary  sleep  by  remaining  under  my  direction,  i.e.  by 
my  remaining  in  connection  with  the  sleeper  through  his  hearing.  As 
soon  as  I  have  reached  this  point  a  further  mastership  over  his  cerebra- 
tion is  an  easy  matter.  I  take  his  arm,  lift  it,  and  declare  that  he  cannot 
lower  it ;  and  he  cannot  with  all  his  efforts.  I  put  both  hands  into  a 
rotating  motion,  and  he  cannot  stop  without  my  permission.  I  declare 
that  his  hand,  which  I  touch,  is  not  sensitive,  and  no  prick  of  a  needle  is 
felt  any  longer.  I  give  him  water  to  drink,  declaring  that  it  is  chocolate ; 
he  tastes  the  chocolate.  I  tell  him  to  open  his  eyes,  make  the  dead 
appear  before  him,  make  him  hear  music  which  does  not  exist,  assure  him 
that  he  is  a  piece  of  wood,  another  person ;  in  short,  any  fantastic  non- 
sense ;  he  feels  it,  believes  it,  lives  through  it.  I  awake  him  when  I  want 
to,  put  him  asleep  by  another  word  in  a  quarter  of  a  second,  and  allow 
him  to  either  remember  or  forget  everything  that  has  been  said  or  done 
to  him.  In  short,  I  make  his  cerebration  play  as  in  a  dream,  but  fol- 
lowing my  orders,  surprise  himself  and  all  the  spectators,  and  gain  with 
the  public  the  name  of  an  accomplished  magician.  The  whole  trick  con- 
sists in  getting,  to  start  with,  an  easily  suggestible  person,  readily 
passing  into  somnambulism.  If  one  is  shown  to  be  hypnotized,  the 
•others  follow  like  the  sheep  of  Panurge.  The  case  described  was  that  of 
a  person  easily  put  into  artificial  somnambulism.  He  need  not  be  a  spon- 
taneous somnambulist  for  this  purpose.  The  latter  are  rather  rare, 
whereas  fully  twenty-five  per  cent  of  mankind  can  be  thrown  into  arti- 
ficial somnambulism.  The  spontaneous  somnambulism,  however,  usually 
represents  the  autohypnosis  of  a  hysterical  person. 

With  others  the  matter  is  slower  and  more  difficult,  although  it  is 
facilitated  by  example  (imitation).  Many  suggestions  may  at  first  be 
without  effect ;  but  with  patience  and  practice  one  obtains  at  least  a  par- 
tial influence  in  ninety-six  per  cent  of  men.  The  person  to  be  hypno- 
tized must  be  neither  insane  nor  in  a  state  of  emotion,  of  excitement,  or 
fear.  He  must  before  all  be  treated  in  a  friendly  and  quieting  manner. 
Flies  are  caught  with  honey.  First  you  must  gain  his  confidence.  Put 
him  into  a  comfortable  easy-chair,  the  head  resting ;  put  the  right  hand  on 
the  forehead,  tell  him  to  look  into  your  eye,  and  explain  to  him  that  you 
are  going  to  let  him  fall  asleep,  or,  at  least,  to  influence  him.     According 


Hypnotism.  421 

to  Bernheim,  you  have  him  look  at  two  fingers  of  the  left  hand,  after  a 
few  seconds  lower  them  slowly  in  order  to  make  the  eyelids  sink  and,  if 
the  eyes  do  not  close  by  themselves,  you  order  them  to  be  shut.  Then 
you  begin  with  easy  suggestions,  and  pass  to  more  difficult  ones  as  soon 
as  the  others  succeed.  By  no  means  all  suggestions  succeed  with  all 
people.  According  to  the  success  of  the  more  important  categories,  one 
may  distinguish  three  or  four  degrees  of  hypnotism,  of  course  with 
numerous  transitions:  — 

1.  Somnambulism,  in  which  practically  everything  succeeds. 

2.  Deep  sleep,  in  which  at  least  amnesia  for  the  time  of  the  hypnosis 
is  obtained. 

3.  Hypotaxia,  in  which  the  hypnotized  yield  to  most  suggestions,  but 
have  the  subjective  feeling  of  being  awake  and  remember  everything 
afterward. 

4.  Somnolence,  in  which  only  few  suggestions  succeed,  and  in  which 
the  hypnotized  can  resist  with  some  effort. 

There  are,  however,  cases  of  deep  sleep  with  little  suggestibility  and, 
again,  others  of  simple  hypotaxia  with  very  great  suggestibility,  but  with- 
out amnesia.  Moreover,  the  hypnotizer  can  at  any  time  transfer  a 
somnambulist  into  one  of  the  other  degrees,  according  to  suggestion. 

The  following  are  a  few  especially  interesting  phenomena  which  suc- 
ceed chiefly  in  somnambulists  :  — 

Posthypnotic  Suggestions. 

You  declare  that  a  certain  phenomenon  will  take  place  after  awaking, 
during  the  waking  condition  ;  for  instance,  he  will  feel,  do,  see,  or  think 
some  particular  thing.    This  actually  occurs  as  foretold  in  the  suggestion. 

Suggestion  a  Scheance  (to  take  effect  at  a  definite  time). 

You  suggest  the  same  thing  for  a  later  time  ;  for  instance,  the  next 
day  or  a  week  afterward,  or  even  later.  This,  too,  usually  succeeds  in 
somnambulists  with  a  little  patience  and  practice. 

Suggestion  in  the  Waking  Condition. 

After  a  little  practice  of  the  subject  almost  every  suggestion  succeeds 
nearly  as  well  in  the  waking  condition  as  during  sleep  or  a  somnolent 
state. 


422  August  For  el : 

Not  only  laymen,  but  also  many  physicians,  have  imagined  that 
hypnosis  and  wake-suggestion  are  totally  different  things.  Nobody  can 
show  his  ignorance  of  this  question  more  thoroughly  than  by  such  a  state- 
ment. Sleep,  i.e.  the  subjective  sensation  of  sleep  of  the  person  hypno- 
tized, is  merely  a  generalization  of  the  suggested  dissociation  in  the  sense 
of  ordinary  sleep.  When  this  generalization  becomes  too  broad  and  the 
hypnotizer  leaves  the  subject,  he  may  at  times  lose  the  "  rapport "  with 
the  subject,  and  when  he  tries  to  give  further  suggestions  he  may  fail  to 
succeed  or  he  awakes  the  subject,  just  as  out  of  ordinary  sleep.  It 
requires  some  precaution  to  reestablish  the  connection  or  "  rapport "  with- 
out putting  an  end  to  the  sleep.  On  the  other  hand,  in  a  circumscribed 
suggestion,  in  a  completely  waking  state,  it  is  easiest  to  show  the  symp- 
tom of  localized  dissociation.  As  soon,  however,  as  you  increase  the 
number  of  suggestions,  i.e.  of  dissociations,  in  a  perfectly  waking  condi- 
tion, you  see  how  the  looks  of  the  hypnotized  change,  become  more 
dreamy  ;  in  other  words,  how  the  dissociations  become  more  generalized 
and  produce  a  state  resembling  general  sleep.  Beaunis  and  others  tried 
to  make  out  that  this  condition  in  complicated  wake-suggestions  and  that 
of  execution  of  post-hypnotic  suggestions  —  practically  the  same  thing  — 
is  something  peculiar,  a  "veille  somnambulique."  This  is  quite  unnec- 
essary. We  are  dealing  merely  with  a  more  or  less  localized  or  general- 
ized condition  of  dissociations  or  sleep.  It  is  true  it  differs  from  ordinary 
hypnosis,  because  in  the  latter  a  great  part  of  brain-activity  is  not  influ- 
enced by  the  hypnotizer,  viz.  the  spontaneous  impulses  of  the  hypnotized ; 
whereas  in  the  intentional  wake-suggestions  everything  is  governed  by 
the  hypnotizer.  Spontaneous  is,  of  course,  not  to  be  taken  in  the  sense 
of  undetermined  free  will,  which  does  not  exist.  What  we  understand 
by  "  spontaneous  "  is  merely  the  resultant  of  all  actual  and  past  plastic 
and  automatic  brain  activities  as  they  are  inherited  and  developed  under 
the  external  influences  during  life. 

Suggested  Falsifications  of  Memory. 

This  is  one  of  the  most  surprising  illusions  produced  by  suggestion, 
described  in  a  masterly  manner  by  Bernheim.  You  suggest  to  some  one 
that  he  remembers  accurately  to  have  done,  experienced,  seen,  or  heard 
something,  while  there  is  absolutely  no  truth  in  it.  This  succeeds 
remarkably   well.      If   external    conditions   make   it   possible  very   dan- 


Hypnotism,  423 

gerous  false  witnesses  might  be  produced  in  this  way.  Children  espe- 
cially are  surprisingly  disposed  to  such  suggestions ;  also  hysterical 
women,  and  even  normal  persons.  For  this  it  does  not  take  a  professional 
hypnotizer.  Ordinary  attorneys,  and  also  physicians,  obtain  sometimes 
unknowingly  such  suggested  confessions  or  symptoms.  Curiously  enough 
it  is  sufficient  to  suggest  the  chief  points  of  the  situation,  and  to  leave 
the  rest  to  the  imagination  of  the  subject.  He  completes  himself  every- 
thing that  was  missing  in  the  suggestion  given,  and  furnishes  a  mass  of 
precise  details,  which  he  makes  up,  and  believes  in,  and  by  which  the 
deception  is  increased.  Conscientious  judges  will,  of  course,  find  that 
the  statement  does  not  agree  with  the  facts  ;  but  unfortunately  sufficient 
pains  are  not  always  taken.  We  cannot  say  that  the  witness  lies ;  he 
speaks  with  the  greatest  conviction,  and  makes  a  deep  impression  on  the 
audience,  especially  on  the  jury. 

Thus  we  see  a  series  of  phenomena,  the  beginning  of  which  is  insig- 
nificant, and  which  all  occur,  more  or  less,  in  normal  sleep  and  in  certain 
people,  which,  however,  when  called  forth  rapidly  and  in  a  condensed 
form,  makes  a  very  baffling,  confusing,  and  almost  miraculous  impression. 
Especially  confusing  are  the  mass-suggestions,  which  take  hold  of  a  great 
number  of  enthusiastic  believers,  produce  hallucinations  of  all  senses, 
even  of  the  tactile  sense,  and  thus  create  convincing  witnesses  for  appari- 
tions, even  for  "materialized"  spirits.  Such  is  indeed  the  great  tendency 
of  our  brain  toward  illusions.  Only  the  more  thorough  psychologists  are 
less  surprised  by  these  phenomena,  because  normal  psychology  has  led 
them  already  to  similar  concepts. 

The  essential  feature  of  suggestion  is  evidently  the  production  of  a 
sleeplike  dissociation  of  brain  activity  by  the  means  of  ideas.  Dissocia- 
tion is  used  to  call  forth  inhibition,  facilitations,  hallucinations,  reenforce- 
ment  of  stimuli,  decisions,  impulses,  affects,  etc.  A  further  characteristic 
feature  is  that  the  person  influenced  is  never  really  conscious  of  the 
mechanism  of  the  actual  realization  of  a  suggestion.  In  a  general  way 
suggestion  makes  it  possible  to  eliminate  consciousness,  i.e.  conscious 
memory,  from  any  phenomenon  whatever,  and  to  bring  it  into  the  circuit 
again.  You  may  make  the  "  skin "  (or  rather  the  parts  of  the  brain 
connected  with  it)  totally  insensitive  to  pricks,  and  yet  later  make  con- 
scious the  sensation  which  was  not  actually  present  at  the  moment  of  the 
prick.  Or  you  may  produce  the  sensation  of  a  prick  and  later  make  the 
subject  amnesic  for  the  pain  felt,  so  that  he  will  emphatically  assure  you 


424  August  Forel: 

that  he  did  not  feel  anything,  although  this  is  not  true.  Again,  you  may 
suggest  the  pain  of  a  prick  which  never  occurred.  In  short,  a  weird  play 
is  possible  with  memory,  consciousness,  motion,  and  sensation  in  som- 
nambulists. 

The  effect  of  facilitating  or  inhibiting  suggestions  goes  even  further. 
It  may  involve  the  sympathetic,  and  call  for,  or  arrest,  menstrual  hemor- 
rhages, and  influence  blushing,  bleeding  from  the  nose,  peristalsis,  etc. 
Constipation,  as  well  as  menorrhagia,  can  be  cured  as  if  by  miracle ;  per- 
spiration and  even  the  pains  of  labor  can  be  influenced.  Surgical  anaes- 
thesia is  quite  often  easily  obtained.  Even  blistering  of  the  skin  has 
been  produced  by  Wetterstrand  beyond  doubt. 

All  these  things  are  continually  doubted,  especially  by  our  esteemed 
colleagues,  the  physicians,  and  the  bona  fides  of  the  hypnotized  is  continu- 
ally denied.  They  cry :  Mystification !  Illusion  !  I  hardly  care  to  men- 
tion as  a  proof  that  I  had  several  women  controlled  to  whom  I  suggested 
menstruation  to  take  place  on  a  definite  day  of  each  month,  exactly  at 
7  A.M.,  to  last  three  days  exactly,  not  merely  once,  but  after  the  sugges- 
tion had  had  its  regular  effect  for  months.  After  all,  theoretical  criti- 
cisms can  always  be  made  against  all  such  controls.  If,  however,  I  submit 
to  your  consideration  the  fact  that  the  many  thousands  who  were  hypno- 
tized by  Liebault,  Bernheim,  Wetterstrand,  van  Renterghem,  Vogt,  and 
myself,  almost  all  came  in  order  to  be  cured  of  some  disorder,  and 
certainly  not  in  order  to  deceive  me,  the  objection  that  it  might  be  hum- 
bug falls  naturally,  especially  if  you  consider  the  regularity  of  the 
phenomena.  It  would  be  inconceivable  that  thousands  of  independent 
people,  who  come  to  a  physician  in  order  to  be  cured,  should  agree  on  the 
same  story  to  deceive  the  physician  in  the  same  manner^  and  to  simulate 
both  hypnosis  and  cure.  These  considerations  alone  demonstrate  the 
absurdity  of  the  objection.  Yet  if  I  mention  cases  of  perfectly  honorable 
and  loyal  men  and  friends  whom  I  have  cured  of  constipation  and  similar 
things,  if  I  mention  a  professor  of  surgery  whom  I  made  anaesthetic  and 
again  sensitive  in  a  quarter  of  a  second,  not  only  in  hypnosis  but  also  in 
the  waking  state,  such  a  hackneyed  objection  might  finally  be  dropped. 
It  is  chiefly  traceable  to  a  fundamental  ignorance  of  psychology  and  of  the 
life  of  the  brain  on  the  part  of  the  majority  of  physicians.  Universities 
ought  to  put  an  end  to  this.  It  is,  after  all,  by  no  means  astonishing 
that  a  dynamo  weighing  three  pounds,  as  the  brain  does,  should  be  able 
to  produce  strong  effects  on  the  circulation,  peristalsis,  etc.,  by  means  of 


Hypnotism.  425 

the  neurokyme  current  through  the  peripheral  nerves  and  ganglia.  And 
if  we  are  obliged  to  admit  that  an  affect  or  a  dream  may  have  grave  and 
lasting  psychological  consequences,  such  as  paralysis,  convulsions,  pains, 
etc.,  why  should  not  a  suggestion  be  able  to  undo  such  consequences  ? 

We  cannot  help  admitting  that,  so  far,  we  have  greatly  underrated 
the  dynamic  effects  of  the  neurokyme  in  the  brain,  both  on  its  evil  and  on 
its  good  side.  We  must  go  farther  and  declare  that  many  diseases  which 
internal  medicine,  gynecology,  etc.,  have  been  in  the  habit  of  treating  from 
a  local  point  of  view  are  nothing  but  affections  of  the  brain  which  ought 
to  be  treated  by  suggestion  alone.  I  merely  speak  of  habitual  constipa- 
tion, of  sleeplessness,  of  chlorosis,  of  most  dyspepsias,  and  of  most  men- 
strual disorders.  And  further,  we  must  claim  that  a  larger  number  of  our 
so-called  remedies,  such  as  electro-therapeutics,  balneotherapy,  many 
prescriptions,  etc.,  cure  merely  by  suggestion,  and  by  no  means  through 
some  imaginary  specific  action.  The  irregularity  of  their  results,  indica- 
tions, and  application  prove  this  sufficiently.  It  must  be  admitted  that 
such  a  remedy  gives,  in  many  cases,  a  stronger  suggestion  than  mere 
verbal  suggestion.  In  America,  we  ought  not  to  forget  the  famous 
Keeley  Gold  Cure  for  inebriates,  as  a  beautiful  instance.  Since  Keeley 
suggested  total  abstinence,  he  was  bound  to  have  lasting  results. 

Let  us  not  forget  that  therapeutic  results  of  suggestion  are  nothing 
but  lasting  post-hypnotic  effects,  which,  however,  like  everything  normal, 
have  a  tendency  to  become  lasting.  We  do  not  put  anything  new  into 
the  body ;  we  merely  lead  the  nerve  paths  back  to  the  normal  dynamic 
course. 

It  is  rarely  possible  to  hypnotize  a  person  against  his  will,  because 
confidence  is  the  first  condition  of  success.  As  soon  as  the  hypnotized 
loses  confidence  in  the  hypnotizer,  the  influence  of  the  latter  is  usually 
over.  The  brain  does  not  submit  any  longer  to  voluntary  dissociation, 
but  it  associates  and  concentrates  all  its  energy  against  the  lightly  built 
dynamic  structure. 

There  remain  a  few  special  points  :  — 

Autosuggestion.  —  By  this  we  mean  suggestions  which  arise  spontane- 
ously, or  at  least  without  intention. 

Hypnosis  and  Hysteria.  —  It  was  a  serious  blunder  of  Charcot,  and 
especially  of  his  pupils,  to  mistake  hypnotism  for  hysteria,  i.e.  a  normal 
fundamental  quality  of  the  human  brain  for  a  pathological  condition.  It 
was,  therefore,  inevitable  that  the  Paris  school  of  hypnotism  had  to  yield 


426  August  Forel : 

to  that  of  Nancy.  Bernheim  showed  quite  correctly  that  the  so-called 
great  hypnosis  of  Charcot,  with  its  supposed  three  phases  appearing  on 
definite  stimuli,  was  nothing  but  an  artefact  by  suggestion  in  pathological 
hysterical  subjects. 

Nevertheless,  hysteria  deserves  special  mention  here,  because  its  funda- 
mental symptom  co7isists precisely  in  a  pathological  exaggeration  and  degenera- 
tion of  dissociahility  or  auto  suggestibility.  The  hysterical,  men  and  women, 
are,  moreover,  known  to  be  much  predisposed  to  convulsions,  so  that  the 
hysterical  react  peculiarly  to  hypnosis.  They  are,  as  a  rule,  very  sensitive 
to  all  hypnotic  procedures,  but  exceedingly  difficult  to  direct.  They  add 
to  every  suggestion  a  mass  of  autosuggestions,  begin  to  get  convulsions 
or  headaches,  or  all  sorts  of  other  disorders  which  their  brain  adds  on 
account  of  its  oversensitiveness  and  excessive  dissociahility.  So  it  easily 
happens  that  for  one  pathological  symptom  removed  by  suggestion,  auto- 
suggestion favors  one  with  three  new  ones.  Hence,  hypnosis  is  an 
excellent,  though  double-edged,  reagent  for  testing  a  hysterical  subject. 
As  a  rule,  however,  it  will  be  possible  to  see  after  one  attempt  how  an  un- 
obtrusive and  well-calculated  suggestion  may  suffice  in  a  conversation  with- 
out the  title  "  hypnosis,"  and  in  a  perfect  waking  state.  An  awkward 
hypnotizer,  or  one  ignorant  of  hysteria,  will  usually  do  harm  to  the 
hysterical,  produce  hj^sterical  attacks,  etc.  The  hysterical  are  apt  to 
pass  into  deep  cataleptic,  and  even  lethargic,  conditions  from  which  they 
are  difficult  to  rouse.  In  short,  to  play  on  them  with  hypnotism  is  play- 
ing with  fire.  All  the  unintentional  damage  which  is  attributed  to 
hypnotism  concerns  hysterical  subjects.  I  therefore  tell  every  physician 
who  wants  to  hypnotize  :  "  Beware  especially  of  the  hysterical,  and  do 
not  run  any  risk  before  you  sit  well  in  the  saddle."  Suggestion  can  do 
much  good  in  the  hysterical,  but  the  physician  must  proceed  exceedingly 
cautiously,  individualizing,  without  even  mentioning  the  word  hypnotism. 

Crime  and  Hypnosis. 

This  chapter  was  exaggerated  to  the  extreme  by  Liegeois,  and  dealt 
with  too  lightly  by  Delboeuf.  That  misuse,  especially  sexual  misuse,  of 
hypnotized  persons,  may  occur  once  in  a  while,  is  certain  and  possible, 
especially  in  deep  hypnosis,  in  hysterical  lethargy,  etc.  Even  more 
dangerous  is,  however,  the  blackmailing  by  hysterical  impostors.  Hence 
the  rule  :  Never  hypnotize  a  woman  alone,  without  a  witness.     That  the 


Hyp7iotism.  427 

hypnotized  might  be  used  for  crime  is  theoretically  possible  and  experi- 
mentally proved.  But  no  such  case  has  really  occurred  yet.  False  testi- 
mony through  suggested  falsifications  of  memory  is  about  the  most  serious 
possibility.  Abnormal  love-affairs  of  pathological  persons,  especially  of 
the  hysterical  or  of  pathological  impostors,  in  which  hypnotism  plays  a 
r61e  (case  of  Czinsky,  etc.)  rather  belong  to  psychiatry.  Of  late  those 
suffering  from  paranoia  and  other  forms  of  insanity  show  a  predilection 
for  the  delusion  that  they  are  secretly  hypnotized. 

Crimes  through  hypnosis  are  probably  so  rare  because,  as  is  said  above, 
confidence  is  the  first  condition  of  hypnosis. 

The  insane  can  usually  not  be  hypnotized,  because  the  instrumental 
dynamo,  the  brain,  fails  to  work  properly,  attention  is  defective,  etc. 

One  can  hypnotize  only  in  one's  mother  tongue,  or  in  another  lan- 
guage which  one  knows  very  well,  for  it  takes,  before  all,  great  certainty 
and  rapidity,  and  a  blunder  in  a  foreign  language  which  makes  it  difficult 
to  understand,  disturbs  the  "  rapport "  considerably. 

For  the  purpose  of  watching  patients  dangerous  to  themselves,  I  have 
hypnotized  the  watching  nurses  with  great  success,  and  in  this  way  pro- 
duced a  "  sleeping  night  watch,"  who  watches  much  better  than  a  waking 
person,  and  does  not  become  exhausted  or  overtired.  I  hear  that  my 
successor  at  Ziirich,  Professor  Bleuler,  continues  the  matter  with  equally 
good  success.  I  give  the  nurse  the  suggestion  to  sleep  quite  well,  but  to 
notice  during  his  sleep  every  unusual  action  of  the  patient,  so  that  he 
awakes  at  once  when  the  patient  makes  an  attempt  at  suicide,  and  at  once 
falls  asleep  again  when  the  danger  is  averted.  In  artificial  somnambulism 
this  succeeds  remarkably  well. 

Therapy  of  Nervous  Diseases  by  Work. 

Creneral  Psychotherapy. 

Starting  from  the  experience  that  agricultural  occupation  is  the  best 
for  the  insane,  and  that  the  natural  man  does  not  work  as  one-sidedly  as 
the  "  civilized,"  but  always  has,  as  the  condition  of  getting  along,  depended 
on  a  combination  of  mental  occupation  with  muscular  activity,  I  have  tried 
for  a  number  of  years  to  treat  severe  cases  of  so-called  nervous  diseases 
(neurasthenia,  etc.),  i.e.  psychopathias,  with  such  occupations.  A  severe 
case  which  I  thus  cured  by  agricultural  work  encouraged  me.  Mr. 
Grohmann,  a  civil  engineer,  himself  a  patient,  had  recovered  his  health  by 


428  August  Forel : 

gardening,  and  was  much  interested  in  the  matter.  I  encouraged  him  in 
his  attempt  to  occupy  nervous  patients  in  his  gardens.  This  was  the 
beginning  of  his  institution  for  the  occupation  of  nervous  cases,  which 
increased  from  year  to  year.  Carpentry  was  added  among  other  occupa- 
tions, and  very  good  results  were  obtained  in  severe  cases.  P.  J.  Moebius 
later  gave  the  method  much  support,  and  the  data  were  published  in  the 
dissertation  of  Menier  (Ziirich),  and  later  more  fully  by  Grohmann  him- 
self. 

Grohmann  emphasizes  the  observation  that  a  combination  of  his  treat- 
ment with  suggestions  by  Dr.  Ringier  in  Ziirich  led  very  frequently  to 
good  results. 

My  principal  idea  in  the  matter  was  that  not  the  muscular  labor  as 
such,  but  especially  the  centrifugal  concentration  of  attention  on  deter- 
mined muscular  innervation  for  an  occupation,  mentally  satisfying  and 
with  a  purpose,  diverts  the  brain  from  pathological  activities,  and  acts  as 
a  cure.  Stupid  muscular  labor,  as  gymnastics,  dumb-bells,  and  turning  of 
the  ergostat,  does  not  give  any  satisfaction,  and,  above  all,  does  not  keep 
the  mind  or  attention  from  going  astray.  Moreover,  such  useless  activi- 
ties cannot  be  pursued  for  any  length  of  time  as  a  real  pursuit. 

Now  1  should  like  to  go  a  step  farther  to-day,  and  to  sketch  with  a 
few  cases  a  partially  new  chapter  of  psychotherapy,  not  touched  upon  by 
me  so  far. 

Not  all  neuropaths  are  fit  patients  for  horticultural,  agricultural, 
or  other  work,  nor  is  the  pathology  of  brain  life  done  justice  to  merely 
by  the  ordinary  suggestions  of  sound  sleep,  appetite,  and  like  functions. 
You  further  know  that  genius  and  insanity  are  somewhat  related. 
Whereas,  however,  it  is  well  known  that  many  a  genius  perished  with 
insanity,  it  is  perhaps  less  clear  to  many  physicians  that  under  the  picture 
of  hysteria  or  other  psychopathias,  many  a  genius,  or  at  least  many  a 
talent,  may  slumber  and  fret  like  a  bird  in  a  cage,  and  also  that  the  thera- 
peutic cant  of  neurologists  paralyzes  the  wings  of  the  bird  instead  of 
liberating  them.  Here,  if  anywhere,  a  correct  diagnosis  and  individualiz- 
ing treatment  is  necessary.  To  be  sure,  not  everybody  who  feels  himself 
to  be  a  genius  is  a  genius.  The  experience  of  the  alienist  must  find  out 
of  the  hundreds  of  defective  brains  suffering  from  exaltation  and  mental 
weakness,  the  few  which  are  not  really  defective,  but  contain  a  wealth 
of  high  talent,  the  development  of  which  is  inhibited  or  paralyzed  by 
certain  disorders.     If,  however,  you  have  discovered  such  a  hidden,  tied- 


Hypnotism.  429 

down  treasure  among  the  numerous  nervous  patients  (brain-patients  or 
encephalopaths),  it  is  your  grand  duty  to  leave  the  path  of  cant, 
and  to  restore  the  wings  to  the  eagle.  Hypnosis  and  occupation  with 
manual  labor  may  be  a  very  helpful  accessory  remedy ;  but  they  are  not 
the  chief  thing.  It  is  necessary  to  gain  the  full  confidence  of  the  patient 
by  affection  and  by  penetrating  into  all  the  sides  of  his  mental  life,  to 
make  every  fibre  of  his  emotional  life  vibrate.  Let  the  patient  tell  you 
the  story  of  his  entire  life,  live  it  over  again  with  him,  and  allow  yourself 
to  be  thoroughly  penetrated  by  his  feelings.  In  this  you  should,  of 
course,  never  forget  the  sexual  feeling  which  varies  so  strongly  from  one 
case  to  another.  But  it  should  not  be  examined  after  the  ordinary  medi- 
cal routine,  which  usually  considers  only  the  seminal  emissions  and  the 
coitus ;  but  with  full  consideration  of  all  the  loftier  vibrations  connected 
with  the  sexual  life.  This  being  done,  you  search  for  the  real  definitive 
aim  in  the  life  of  the  patient,  and  lead  him  with  determination  and  con- 
fidence. It  is  a  cause  of  much  surprise  to  see  all  the  psychopathologi- 
cal  disorders  disappear  as  if  by  witchcraft,  and  to  watch  how  the  unhappy, 
incapable,  nervous  wreck  becomes  an  energetic,  efficient  person,  who 
may  amaze  others  by  his  working  capacity,  and  remains  a  warm  friend 
to  the  physician  who  understood  him.  A  miserable  person  becomes 
happy;  a  "failure,"  a  "talent"  or  even  a  "genius";  a  patient,  a  healthy 
being. 

Allow  me  to  give  briefly  a  few  instances.  My  friends  may  recog- 
nize themselves,  but  will  pardon  this  publication  in  the  interest  of 
mankind. 

1.  A  highly  educated  young  lady,  the  daughter  of  a  talented  father 
and  a  very  nervous  mother,  had  the  reputation  of  being  less  endowed 
than  her  sisters,  was  nervous,  and  became  more  and  more  hysterical.  She 
finally  developed  very  marked  paralysis,  and  was  brought  to  the  hospital 
for  the  insane.  At  first  she  was  almost  completely  cured  by  ordinary 
hypnosis ;  but  after  a  number  of  months  she  had  a  relapse,  with  almost 
total  inability  to  walk.  She  was  again  cured  by  continual  agricultural 
work  with  farmers.  But  she  felt  unhappy  over  not  having  an  aim  in 
life.  Not  without  hesitation  I  allowed  her  to  yield  to  her  anxious  desire 
to  become  a  nurse ;  her  parents  were  much  afraid  of  the  night  service. 
But  the  latter  was  endured  without  trouble  with  the  help  of  a  few  sugges- 
tions regarding  it.  She  took  up  her  work  enthusiastically,  carried  it  out 
with  all  its  trials  and  fatigues,  and  became  more  and  more  active  in  every 


430  August  Ford: 

direction,  and  to-day  she  is  one  of  the  most  active  members  of  a  com- 
mittee of  philanthropic  ladies,  doing  remarkable  work. 

2.  A  physician  suffered  for  some  time  with  "severe  neurasthenic 
disorders,"  and  tried  in  vain  to  cure  himself  with  all  sorts  of  remedies. 
He  came  to  me  with  his  complaints.  I  encouraged  him,  advised  him  not 
to  consider  all  those  disorders,  and  insisted  on  the  higher  ideals  of  his 
life.  We  agreed  on  a  definite  plan  and  he  left.  Later  he  wrote  me  that 
by  that  one  conversation  he  had  been  cured. 

3.  A  young  man  with  some  hereditary  taint,  from  a  very  religious 
family,  very  talented,  became  "  neurasthenic  "  and  nearly  insane.  He 
attempted  suicide,  and  was  taken  to  various  sanitariums  with  complete 
interruption  of  his  studies  and  very  gloomy  prognosis.  He  was  abso- 
lutely unable  to  work  any  longer,  suffered  from  headache,  sleeplessness, 
and  inability  to  keep  his  attention  on  any  mental  activity.  Gloomy  and 
in  despair,  he  did  not  show  any  symptoms  of  melancholy  inhibition,  etc. 
He  was  quite  clear  concerning  his  "  psychopathia  "  and  "  absolute  failure 
in  life."  He  also  had  suffered  from  various  imperative  ideas  and  actions 
which  had  played  him  many  a  trick.  Sexually  he  was  perfectly  calm. 
He  was  brought  to  me  as  a  case  given  up.  Before  long  the  talent  of  the 
young  man  struck  me.  More  intimate  relations  showed  him  to  be  in  a 
totally  dissatisfied  state  of  mind.  Brought  up  in  strict  orthodoxy,  he 
never  could  believe  in  those  religious  dogmata,  and  therefore  thought 
liimself  to  be  an  outcast  and  lost.  The  forced  formal  training,  too,  with 
which  he  was  brought  up  was  a  source  of  disgust  to  him.  Life  seemed 
aimless  to  him.  First  I  calmed  him  concerning  his  religion,  and  showed 
him  that  one  can  be  a  happy  and  valuable  man  without  any  positive 
belief.  Further,  I  showed  him  that  learning  by  heart  is  the  "  mind  of 
the  mindless,"  and  that  a  mere  understanding  with  interest  stands  much 
higher.  I  told  him  not  to  try  to  learn  anything  further,  but  to  merely 
read  with  interest  what  interested  him,  and  not  to  care  whether  he  kept 
it  or  not.  In  this  way  I  revived  some  confidence  and  some  pleasure  in 
life.  He  began  to  read  his  books  with  interest  and  pleasure,  instead 
of  learning  them  with  disgust.  As  a  philosopher  and  freethinker  he 
returned  to  life,  became  an  enthusiastic  abstainer  and  a  member  of  the 
Independent  Order  of  Good  Templars.  He  helped  me  found  new  lodges. 
My  patient,  who  at  first  required  watching  for  fear  of  suicide,  soon 
became  my  friend  and  associate  in  the  work.  The  nervous  symp- 
toms disappeared,  one  after  another.      Finally  he  made  a  rather  long 


Hy][,notism.  431 

journey  alone  in  a  tropical  country,  returning  completely  cured  and  with 
perfect  self-confidence.  He  resumed  his  studies,  passed  his  final  exami- 
nation summa  cum  laude  a  few  years  later,  was  admired  by  all  his  col- 
leagues for  his  enormous  working  capacity,  and  gives  every  promise  of  a 
splendid  career. 

4.  An  hysterical  lady  consulted  me  —  highly  talented,  but  psycho- 
pathic from  childhood,  with  attacks  of  "grande  hysteric,"  and  greatly 
excited  by  her  living  together  with  her  mother.  Notwithstanding 
numerous  opportunities,  she  did  not  want  to  get  married  for  a  number 
of  intellectual  reasons.  I  tried  hypnosis.  Deep  hysterical  sleep  came  on 
and  convulsions  began  to  show.  I  waked  her  up  with  much  trouble, 
told  her  boldly  the  result  was  deep  beyond  expectation,  that  she  would 
be  cured  in  a  short  time,  and  that  she  had  been  only  too  deeply  influ- 
enced. From  that  time  I  gave  her  merely  wake-suggestions.  In  a 
few  days  almost  all  the  disorders  had  gone,  also  the  constipation, 
and  especially  the  convulsions  (sapienti  sat/}.  I  explained  to  her  that 
she  was  most  in  need  of  work  and  of  a  definite  aim  in  life.  She  did 
not  care  to  found  a  family,  with  some  justification,  but  was  interested 
in  depraved  youth.  Now  she  started  out.  Instead  of  cures  in  water- 
ing places,  electricity,  and  massage,  I  gave  her  a  number  of  books 
on  criminal  anthropology  and  introductions  to  the  directors  of  prisons, 
of  asylums,  of  the  reformatories  for  children,  etc.  She  took  up  the 
work  with  enthusiasm,  joined  the  prohibition  movement  and  the  Inde- 
pendent Order  of  Good  Templars,  visited  prisoners,  the  insane,  destitute 
children,  showed  great  interest  in  everything,  an  equally  good  judgment, 
and  an  astonishing  working  capacity.  She  improved  every  day,  and 
left  in  a  few  weeks  for  a  larger  city,  where  she  wishes  to  continue 
her  studies. 

In  such  cases,  I  should  formerly  have  prescribed  mental  rest,  inac- 
tivity, manual  labor,  or  what  not.  My  patients  did  not  improve.  In 
such  cases  the  brain  is  not  exhausted,  as  one  might  suppose  at  first  sight. 
It  is  merely  misled,  and  works  in  abnormal  paths  ;  its  natural  talents 
starve,  are  inhibited,  and  the  activity  offered  it  does  not  agree  with  it,  or 
certain  scruples  of  a  religious  or  sentimental  kind  paralyze  its  activities, 
and  paths  for  pathological  brain  activity  are  created.  This  we  must 
recognize  and  change  by  a  bold  diversion. 

But  beware  of  believing  every  psychopath  who  poses  as  a  mistaken 
genius  and  wants  to  study  higher  philosophy.     There  are  fifty  cases  of 


432  August  Forel :    Hypnotism. 

these  to  one  of  those  described  above.  For  these,  agriculture  is  as  good 
as  for  imbeciles  and  the  insane.  True  inhibited  greatness  is  not  wont  to 
brag  or  to  think  too  highly  of  itself.  We  must  look  after  it,  must  seek 
it  and  find  it.  Then  we  can  go  to  the  root  of  the  matter  and  not  remain 
content  with  mere  trivial  suggestions  about  gardening  or  carpentry. 


A   SKETCH   OF   THE   BIOLOGY   OF   ANTS. 

By  Professor  August  Forel. 

Together  with  the  bees  and  the  wasps,  the  real  ants  belong  to  the 
insect  family  of  hymenoptera,  whereas  the  termites,  or  white  ants,  belong, 
like  the  dragon-flies,  to  the  neuroptera.  All  these  insects  live  in  social 
organizations.  More  than  all  the  rest,  the  ants  have  developed  social 
life  most  highly  and  variedly.  This  is  why  they  deserve  our  special 
interest.  They  not  only  present  an  innumerable  array  of  individuals,  but 
also  a  magnificent  variety  of  forms.  Nearly  3000  species,  divided  into 
154  genera,  are  already  described  from  the  five  continents,  and  this  number 
continues  growing  every  year. 

The  social  state  of  ants  has  brought  about  a  peculiar  phenomenon 
called  polymorphism  of  the  species.  Just  as  the  difference  of  sex  in  man 
and  animals  is  generally  marked  by  so-called  correlative  differences  of 
organization  (as,  for  instance,  the  beard  in  man),  so  we  find  in  certain 
animals  that  these  differences  become  especially  pronounced  (compare, 
for  instance,  the  cock  and  the  hen).  In  the  ants,  the  difference  of  the 
sexes  becomes  so  excessive  that  the  females  and  the  males  look  like  dif- 
ferent animals.  But  that  is  not  all.  An  additional  differentiation  takes 
place  in  the  species,  in  the  female  germs  ;  a  certain  number  develop  into 
a  second  category  of  females  with  totally  different  shape  of  the  body, 
much  diminished  ovaries,  without  wings,  but  with  a  more  highly  devel- 
oped brain.  This  specialized  category  of  females  is  called  the  "  working 
ant."  In  many  species,  even  a  third  specialization  of  the  female  sex  has 
formed,  with  powerful  head  and  strong  jaws,  called  "soldiers."  The 
females  and  the  males  are  usually  winged,  the  workers  and  the  soldiers 
always  without  wings.  Consequently,  a  family  or  a  state  of  ants  of  any 
kind  consists  of  three  or  four  different  forms  of  adult  individuals.  In 
rare  instances,  additional  forms  exist.  Moreover,  there  are  many  species 
in  which  an  incomplete  division  of  the  workers  into  two  categories  with 
transition  forms  occurs  (large,  medium,  and  small  workers).     To  these 

2  F  433 


434  August  Forel: 

we  must  add  the  young  brood,  which  consists  of  eggs,  the  footless  and 
eyeless,  white  and  tender  larva?  or  maggots  of  all  sizes,  according  to  age 
and  sex ;  and,  finally,  the  antlike  nymphs  or  chrysalides.  In  many 
species,  the  larva  spins  a  fine  silk  cocoon,  which  is  erroneously  called 
the  egg.  The  real  ant  eggs  are  extremely  small,  and  look  almost  like  a 
white  poAvder. 

The  architecture  of  the  ant  body  shows  several  important  social 
peculiarities.  The  real  brain,  independent  of  the  sense  organs,  is  rela- 
tively very  large  in  the  worker  and  the  soldier,  smaller  in  the  female,  and 
almost  rudimentary  in  the  male,  in  accordance  with  the  fact  that  the  male 
ant  plays  a  pitiably  transient  and  good-for-nothing  role,  notwithstanding 
its  powerful  eyes  and  strong  wings.  Its  immense  imbecility  and  help- 
lessness, in  contrast  with  the  well-developed  senses,  are  a  clear  expression 
of  its  lack  of  brain.  The  real  brain,  Dujardin's  pediculated  body, 
possesses  a  highly  developed,  small-celled  cerebral  cortex,  especially  in 
the  worker. 

The  ants  possess  a  social  stomach  or  crop.  It  is  situated  at  the 
entrance  to  the  abdomen,  is  very  elastic  (when  it  is  overfed,  the  cubic 
contents  of  the  abdomen  may  be  ten  times  enlarged),  and  does  not  digest, 
since  it  has  no  glands.  Its  undigested  contents  can  be  vomited  forth  at 
any  time  by  the  ant  and  distributed  to  its  fellows,  or  to  the  larvae  by 
feeding  from  mouth  to  mouth.  The  mutual  feeding  is  one  of  the  vital 
conditions  of  the  state  of  ants.  Behind  the  crop  lies  the  chewing,  or 
pumping,  stomach.  It  has  four  hard  valves,  which  usually  close  hermetic- 
ally the  digestive  tract  of  the  ant.  When  the  ant  wants  to  eat,  it  opens 
the  valves  and  pumps  some  of  the  contents  of  the  crop  into  its  peculiar, 
individual  stomach,  which  is  lined  with  digestive  glands  and  where  diges- 
tion begins.  I  have  demonstrated  these  conditions  by  an  experiment. 
I  gave  some  honey  stained  with  Berlin  blue  to  a  hungry  ant.  After  it 
had  eaten  very  eagerly,  I  put  it  with  a  few  equally  hungry  companions, 
who  at  once  surrounded  it,  begging.  They  all  were  filled  with  blue 
droplets  before  long.  I  then  dissected  one  after  another  and  found  that 
the  first  stomach,  filled  with  the  blue  mass,  had  not  at  first  allowed  a 
trace  of  the  blue  fluid  to  pass  into  the  chewing  stomach  and  into  the 
digestive  stomach.  Only,  during  the  following  days,  the  digestive 
stomach  slowly  became  stained  more  and  more  blue. 

On  the  fore  legs  the  ants  have  a  fine,  spurlike  comb  which  they  use  to 
clean  the  rest  of  the  body.     This  is  very  necessary  in  the  busy  workers. 


Biology  of  Ants.  435 

In  the  mouth,  too,  they  have  a  comb  with  which  they  clean  the  combs  of 
the  legs,  the  larvae,  and  their  companions. 

Of  great  importance  are  further  the  mandibula,  or  upper  jaws,  which 
are  usually  dentated  and  serve  as  grasping  tongue,  biting  weapon,  mortar 
spoon,  carrying  instrument,  scissors,  etc.  They  replace  our  hands,  our 
weapons,  our  scissors  and  knives.  In  the  mouth  they  have,  further,  a 
tongue  for  licking,  with  fine  organs  of  taste. 

The  most  important  social  organs  of  the  ant  are,  however,  the  anten- 
nfB,  or  feelers.  They  contain  exceedingly  delicate  and  numerous  sense- 
organs  for  the  tactile  sense  and  odor,  terminating  in  hairlike  structures. 
The  function  of  these  sense-organs  is  experimentally  established.  It  is 
especially  remarkable  that  this  protruding  and  mobile  olfactory  organ  not 
only  gives  the  ant  information  on  the  chemical  constitution  of  bodies, 
through  contact  (I  called  this  contact-odor  of  the  insects),  but  also  makes 
possible  an  appreciation  of  space  by  olfaction,  owing  to  position  and 
motility,  an  ability  which  we,  with  our  invaginated,  rudimentary  olfactory 
organs,  can  form  no  conception  of.  This  appreciation  of  space  is  possible, 
since  the  different  nerve  endings  may  convey  to  the  brain  simultaneously, 
or  in  successive  moments,  the  impression  of  the  various  chemical  proper- 
ties (odors)  of  various  objects  or  parts  of  objects,  lying  side  by  side. 
Numerous  relations  of  space  are  perceived  for  this  reason,  and  especially, 
owing  to  the  high  mobility  of  the  feelers,  not  merely  by  contact  but 
already  at  a  certain  distance,  at  which  the  differences  of  behind  and 
before,  of  right  and  left,  can  readily  be  furnished  by  smell.  This  ability 
must  produce  a  knowledge  of  space  which  lies  between  that  of  our  tactile 
sense  and  that  of  the  senses  of  hearing  and  seeing.  When  lately  Bethe 
imagined  he  had  discovered  a  "  polarization  "  of  the  olfactory  traces  of 
the  ants,  he  mistook  and  overlooked  these  conditions  completely.  More- 
over, the  ants  perceive  odor  from  a  distance  with  their  antennse.  It  is 
experimentally  established  that  ants  recognize  one  another  as  friends  or 
foes  merely  by  the  means  of  the  feelers,  as  Huber  supposed  as  early  as 
1810;  and  that,  in  their  migration,  they  are  largely  oriented,  or  guided,  by 
the  feelers,  although  the  eyes,  too,  help  considerably  in  the  orientation  out- 
side of  the  nest.  An  ant  without  feelers  is  lost,  and  at  once  excluded  from 
the  social  life;  whereas  without  eyes  it  may  go  on  working,  recognizing 
its  companions  from  its  enemies,  and  find  its  way,  although  with  more 
difficultj^  at  least  in  the  nest  and  in  its  near  neighborhood. 

Lubbock  has  proved  that  ants  feel  the  ultra  violet  rays  of  the  solar 


436  August  For  el: 

spectrum  which  we  do  not  see.  With  the  help  of  complicated  experi- 
ments (by  varnishing  the  eyes,  or  by  the  application  of  aesculin  which 
absorbs  the  ultra  violet  rays)  on  the  known  instincts  of  ants,  I  have  dem- 
onstrated that  they  see  the  ultra  violet  rays  with  the  eyes,  not  photo- 
dermatically,  i.e.  with  the  skin,  as  many  lower  animals  do.  The  flying 
females,  and  especially  the  males,  have  good  eyes,  with  very  distinct 
vision  ;  the  workers,  however,  see  usually  but  poorly. 

The  workers  form  the  most  important  social  elements  of  the  ant  com- 
munity, whereas  the  soldiers  serve  for  certain  special  functions,  and  the 
females  and  males  solely  for  the  propagation  of  the  species. 

The  socialism  of  the  ants  is  limited  to  the  solitary  state  of  the  ant 
colony.  All  the  individuals  of  one  colony  live  up  to  complete  solidarity, 
whereas  the  rest  of  the  world  —  with  but  few  exceptions  —  and  especially 
all  the  other  states  of  ants,  even  of  the  same  species,  are  rather  consist- 
ently treated  as  enemies.  Each  state  builds  one  or  more  nests.  In  these 
the  immense  wealth  of  instinct  in  ants  shows  itself.  Almost  every  single 
species  has  some  peculiarity  in  its  architecture ;  yea,  the  same  species 
knows  how  to  adapt  itself  to  the  varying  conditions,  and  to  build  accord- 
ingly. Our  most  common  European  ant,  occurring  also  in  North  America, 
the  small  dark  brown  Lasius  niger  Linne,  builds  in  the  meadows  large, 
regular  labyrinth-like  hills  of  earth.  In  stony  ground  it  makes  its  nests 
under  stones ;  in  the  woods,  in  rotten  stumps  ;  in  houses,  in  rotten  frames. 
Most  European  and  North  American  species  mine  in  the  earth  labyrinth- 
like complexes  of  galleries  and  rooms,  where  they  nurse  their  brood. 
Many  build  a  dome  of  earth  on  it,  serving,  like  flat  stones,  to  take  up  the 
radiating  heat  of  the  sun.  When  the  sun  shines  in  cool  weather,  the 
ants  carry  their  whole  brood  under  the  cupola  or  under  the  stone.  Dur- 
ing the  night,  or  in  rain  or  in  hot  weather,  everything  is  carried  into  the 
depth.  The  ants  build  with  their  jaws  and  forelegs,  working  up  moist 
earth  into  little  lumps,  during  or  after  a  rain,  and  making  walls  with 
them.  They  are  splendid  masons  and  know  how  to  use  a  blade  of  grass  as 
timber  or  a  leaf  for  a  roof.  Occasionally  a  little  stalk  is  sawed  with  the 
teeth  of  the  upper  jaw  wholly  or  partly  bent,  pulled  sideways,  etc.  I 
recommend  every  friend  of  nature  to  watch  this  activity  after  a  warm 
rain  in  a  meadow. 

Other  ants  with  strong,  hard  jaws  mine  their  nest  in  hard  wood.  In 
a  species  living  in  trunks  of  trees  (^Camponotus  s.  Colobopsis  truncatus)  a 
very  narrow  hole  leads  out.     It  is  constantly  watched  by  a  peculiarly 


Biology  of  Ants,  437 

transformed  soldier  —  its  big  head  just  fills  the  hole  and  is  trimmed 
flat  anteriorly,  so  that  it  closes  the  hole  flush,  like  a  cork.  Even  a 
trained  eye  has  difficulty  to  find  the  hole  stuffed  in  this  manner.  A 
closely  related  species  lives  in  North  America.  Yet  other  species  nest 
under  the  bark  of  trees,  under  stones,  in  rocks  or  cracks  of  walls,  even  in 
walls  of  our  houses.  In  tropical  America  I  found  a  great  number  of  the 
species  in  hollow,  dry  sticks  of  the  brush,  also  in  the  thorns  of  acacia  and 
in  hollow  trees.  The  ant  of  our  woods,  Formica  rufa^  and  its  next  Euro- 
pean and  North  American  cousins  cover  a  dome  of  fir  needles,  small 
fragments  of  wood,  etc.,  which  keep  warm  the  nest,  built  as  a  hollow 
labyrinth.  The  gates  are  opened  by  the  ants  in  the  morning  and  closed 
in  the  evening,  in  excessive  heat  frequently  the  reverse.  Other  ants 
evidently  use  a  resin-like  secretion  of  the  maxillary  gland,  and  cement 
with  it  meal  of  wood,  earth,  plant-fibres,  and  similar  material  to  form 
a  sort  of  cardboard  or  pulp  out  of  which  they  make  wonderful  nests, 
either  in  hollow  trees,  as  our  European  Lasius  fuliginosus  and  Liometopum 
microcephalum  (and  the  North  American  Liometopum  apiculatum'),  or  out- 
side on  branches  of  trees  or  on  trunks,  as  we  have  found  it  in  many 
Central  American  species  of  Azteca  and  Cremastog aster. 

Finally  there  are  ants  which  build  nests  spun  between  the  leaves  of  the 
trees  out  of  a  fine,  silk-like  texture,  as  the  species  Polyrhachis  and  Oeco- 
phylla,  and  in  Costa  Rica  the  Oomponotus  senex  s.  textor.  According  to 
the  most  recent  observations  they  are  said  to  use  their  larvae,  which  fur- 
nish the  thread,  and  which  they  use  with  the  jaws  as  a  spinning  instrument. 
Certain  species  (Formica  exsecta  in  Europe  and  exsectoides  in  the  Alle- 
ghanies)  form  powerful  states  or  colonies,  which,  according  to  McCook, 
may  consist  in  the  Alleghanies  of  up  to  1600  nests,  which  are  all  in  friendly 
relations  with  one  another  and  are  able  to  govern  a  whole  forest. 

How  does  a  colony  form  ?  Huber,  McCook,  Blochmann,  and  Lubbock 
have  established  the  following  facts:  At  a  certain  season,  the  mature 
young  brood,  the  winged  females  and  males,  fly  out  from  all  the  nests  of 
the  same  species.  In  the  air,  on  trees,  or  on  the  tops  of  hills,  a  wild 
mass-wedding  takes  place  in  which  I  was  able  to  establish  mutual,  but 
especially  female,  polygamy.  Shortly  afterward  the  stupid  males  perish 
on  account  of  inability  to  feed  themselves.  The  females  remove  with 
their  own  legs  the  loosely  attached  wings  and  creep  into  the  earth  or  into 
wood,  singly  or  several  together.  They  build  a  little  room,  lay  a  few 
eggs,  and  sparingly  nurse  the  larvae,  or  maggots,  out  of  their  own  body 


438  August  Forel : 

juice  (they  are  very  stout  and  fat)  until  three  or  four  very  small  workers 
have  grown  up.  These  begin  to  work  at  once  and  to  feed  and  care  for 
their  mother  or  mothers,  which  have  nothing  to  do  after  this.  The 
wonderful  feature  is  that  the  mother  or  the  mothers  keep  so  many  sper- 
matozoa in  their  seminal  pocket  from  the  one  multiple  copulation  or 
wedding,  that  they  remain  fertile  for  many  years  and  are  able  to  lay  mill- 
ions of  eggs.  They  evidently  remain  as  a  rule  the  mothers  of  the  entire 
colony  as  long  as  it  exists.  At  least  Lubbock  kept  alive  fertilized  females 
in  artificial  nests  for  eight  and  even  eleven  years,  and  the  existence  of  most 
colonies  of  ants  probably  does  not  last  much  longer.  It  is,  however,  not 
impossible  that  once  in  a  while,  later  on,  a  female  brought  home  by  the 
workers,  or  a  female  of  their  own  progeny  fertilized  already  within  the 
nest,  may  be  added  to  their  number.  Except  in  parasitic  species,  strange 
females  are  always  killed  by  the  workers  of  a  colony.  The  mothers  or 
queens  are  well  cared  for  and  fed  by  the  workers.  Their  sole  work  con- 
sists in  laying  eggs.  A  court  of  workers  constantly  surrounds  the  fertil- 
ized female,  takes  charge  of  the  eggs,  etc. 

The  interior  life  of  an  ant  colony  represents  the  purest  anarchistic 
socialism.  Each  individual  works  for  the  community.  Some  build 
the  nest ;  others  clean  every  corner  of  it ;  yet  others  nurse  the  brood, 
feed  it,  clean  it,  and  carry  it,  according  to  the  temperature,  into  various 
parts  of  the  dwelling.  Others,  again,  leave  the  nest  and  see  to  the  food 
supply  of  the  community  by  filling  first  their  social  crop,  or  first  stomach. 
The  workers  serve  one  another  attentively,  feed,  clean,  and  carry  one 
another,  and  have  a  mutual  understanding  by  means  of  the  feelers 
and  certain  butts.  The  understanding,  as  well  as  the  motor  impulse,  of 
that  language  of  signs,  evidently  depends  on  inherited  instincts,  and 
is  decidedly  quite  limited,  but  must  be  sufficient  for  the  social  require- 
ments. The  males,  and  usually  also  the  females,  are  inactive,  and  are,  the 
former  wholly,  the  latter  largely,  fed  and  cared  for  by  the  workers. 
Toward  the  outside  world  the  whole  number  is  usually  hostile  to  every- 
thing living,  which  leads  to  offensive  and  defensive  wars  and  expeditions, 
the  study  of  which  is  uncommonly  interesting  for  the  comparative 
psychologist. 

As  I  said  before,  the  workers  find  their  way  outside  with  the  help  of 
their  sense  of  smell  and  of  touch,  and  partly,  also,  with  their  eyes.  But 
this  is  frequentl}^  very  difficult  for  them,  and  they  help  one  another  in 
two  ways.     Individuals  with  especially  good  sense  of  smell  (with  stronger 


Biology  of  Afits.  439 

olfactory  bulbs  of  the  antennse)  which  have  found  something  useful  or 
dangerous,  come  home,  butt  impetuously  against  many  companions,  turn 
round,  and  are  accompanied  by  a  number  of  workers  to  the  place  of  the 
finding  or  of  the  danger,  guided  by  means  of  their  sense  of  smell.  On 
the  way  they  often  turn  round  to  find  out  whether  they  are  followed. 
Ants  with  relatively  poorer  sense  of  smell  return  home  after  having  found 
something;  take  hold  of  a  companion  with  the  upper  jaws,  and  induce  him 
to  have  himself  carried  to  the  new  place,  motionless  and  partly  rolled  up. 
The  carried,  apparently  motionless,  ant  sees  and  smells  the  way  all  the 
same,  even  if  it  amounts  to  thirty  or  forty  yards.  She  returns  to  the 
nest  herself  and  again  brings  new  companions  to  the  place  of  emigration. 
In  this  way,  ants  which  have  lost  their  way  have  themselves  carried  home 
when  they  meet  a  companion.  If  for  any  reason  a  colony  of  ants  becomes 
tired  of  its  old  nest,  the  same  course  is  chosen.  The  most  enterprising 
workers  search  for  new  places,  and  the  most  fortunate  and  active  ones 
among  them  finally  bring  the  entire  colony,  with  its  brood,  to  the  new 
site  selected  by  them.  These  migrations  are  exceedingly  instructive, 
since  there  are  competitions  between  two  or  three  new  sites  until  one  is 
victorious,  because  the  ants  come  back  from  the  others  and  reemigrate. 

Every  working  ant  is  capable  of  doing  all  the  labors  mentioned  in 
turn,  although  many  individuals,  especially  always  the  partially  dimor- 
phous forms  of  workers,  usually  have  their  preference  for  the  one  or  the 
other.  Huber  has  shown,  and  I  have  found  it  corroborated  several  times, 
that  ants  completely  separated  recognized  one  another  after  weeks  and 
months,  and  saluted  one  another  as  friends,  merely  by  the  help  of  the 
peculiar  olfactory  organs  of  the  antennae.  This  kind  of  memory  varies 
according  to  the  species. 

There  are  immense  variations  in  the  mode  of  nutrition  of  the  ants, 
and  this  is  one  of  the  most  important  causes  of  variety  of  the  habits,  as 
a  few  instances  will  show. 

The  plant-lice  are  well  known.  On  most  of  our  plants  we  find  these 
tiny,  succulent  parasites,  imbibing  with  their  trunks  the  juice  of  the 
plants,  but  digesting  their  rich  and  ever-present  meals  quite  insufficiently, 
so  that  their  excrements  are  a  clear  fluid  containing  sugar.  It  is  anatomi- 
cally demonstrable  that  these  clear  droplets  are  not  secretions  of  special 
glands,  but  really  the  excrements  of  the  lice.  Most  ants  of  our  regions 
are  in  the  habit  of  considering  the  plant-lice  as  a  kind  of  cattle,  to  look  for 
them  everywhere,  to  tickle  them  with  their  feelers  until  the  louse  passes 


440  Atigust  Forel : 

the  clear  drop,  which  is  at  once  eagerly  sipped  by  the  ant.  When  no  ants 
are  present,  the  louse  waits  longer,  and  finally  kicks  like  a  horse,  at  the 
same  time  spurting  forth  the  drop.  By  this  the  leaves  get  a  brilliant 
coating  of  sugar,  the  so-called  honey  dew.  In  the  manner  described  the 
ants  fill  their  social  stomach  for  the  community.  Certain  species  build 
a  dainty  mason-work  of  stables  for  the  lice  on  the  roots  of  the  plants  in 
their  underground  dwellings,  and  even  take  care  of  the  eggs  of  the  root- 
lice.  Other  species  build  stables  above  ground  with  moist  earth,  and 
galleries  around  the  stalks  of  plants  which  bear  leaf -lice,  in  order  to  pro- 
tect their  wealth  in  cattle  against  attacks  by  strangers.  In  other  regions, 
especially  in  the  tropical  countries,  little  larvse  of  cicadas  and  caterpillars 
of  butterflies  are  used  in  a  similar  way  as  cattle  for  ants.  The  ants 
always  know  enough  to  unite  their  efforts,  in  order  to  lug  home  both 
pieces  of  prey  and  larger  pieces  for  the  construction  of  the  nest.  In 
America,  Africa,  and  India  there  are  ants  (Dorylides)  whose  enormous 
colonies  live  as  nomads  above  or  beneath  the  surface.  They  usually  nest 
for  a  while  in  the  ground  or  in  a  hollow  tree,  whence  they  make  enormous 
expeditions  for  prey,  in  which  they  attack,  kill,  cut  to  pieces,  and  carry 
home  everything  alive  :  cockroaches,  rats,  mice,  spiders,  etc.  When  they 
attack  a  human  habitation,  all  the  inhabitants  are  forced  to  leave  at  once ; 
and  they  are  glad  to  do  so,  because  within  a  few  hours  all  the  vermin, 
big  and  small,  are  chopped  up  and  carried  away.  Small  children  in  the 
cradle  must  be  protected  against  the  intruders  and  taken  away.  But  in 
return  the  house  is  free  of  vermin,  and  very  soon  all  the  ants,  together 
with  their  prey,  have  disappeared.  In  the  Dorylides  the  huge  females 
are  always  devoid  of  wings  and  eyes ;  the  males,  also  very  large,  are 
winged,  however,  and  in  possession  of  powerful  eyes.  In  a  short  excur- 
sion through  Colombia,  I  could  watch  the  expeditions  of  the  Dorylides 
species,  in  part  at  least. 

Far  more  remarkable  even  is  the  mode  of  life  of  the  ants  which 
raise  fungi.  They  belong  to  the  South  American  tribe  of  the  Attini. 
In  their  frequently  very  large  nests  these  animals  form  caves  which 
reach  the  size  of  a  fist.  The  workers  climb  the  trees  in  long  pro- 
cessions, every  worker  cuts  out  a  spherical  piece  of  a  green  leaf  with 
its  strong  jaws,  and  thousands  of  them  return  laden  with  such  leaves. 
They  have  three  sizes  of  workers :  big-headed  giants,  minute  dwarfs, 
and  between  them  a  scale  of  medium-sized  individuals.  The  latter  are 
the  leaf-cutters,  whereas  the  giants  are  at  the   same  time  defenders  of 


Biology  of  Ants.  441 

the  nests  and  crushers  of  the  leaves.  The  harvest  of  leaves  is  prepared 
into  a  kind  of  a  hashed  pulp,  which  is  built  up  in  the  form  of  a  laby- 
rinth, or  rather  sponge.  This  pulp  of  leaves  serves  as  culture  medium 
for  the  spores  of  the  fungus  (^Rhozites  gongylophora  MoUer),  which  are  , 
present  in  the  nest  in  large  quantities.  The  leaf-pulp  rapidly  becomes 
covered  with  a  white  film.  The  army  of  working  dwarfs  watch  that 
the  fungus  does  not  fill  the  nest  and  stifle  its  inhabitants.  Every 
growing  twig  or  thread  is  at  once  cut  off  by  these  pigmies,  hardly  two 
millimetres  long,  until  the  fungus  gets  ready  to  produce  its  second 
form,  which  MoUer  has  called  ant-kohlrabi,  because  they  are  little 
nodes  resembling  miniature  kohlrabi.  The  fungus  produces  immense 
quantities  of  these  kohlrabi,  and  the  whole  ant-colony  lives  on  them. 
But  the  nutritive  power  of  the  pulp  for  the  fungi  is  not  infinite.  As 
soon  as  a  part  of  a  sponge-like  fungus  garden  is  exhausted  and  becomes 
brownish,  it  is  torn  down  by  the  ants  and  thrown  in  small  brown 
grains,  out  of  the  nest,  around  which  they  form  wall-like  hills.  In 
return,  these  parts  are  continually  replaced  by  the  fresh  supplies  of 
leaves.  Thus  they  work  continually,  day  and  night,  throughout  the 
year,  the  leaf-cutters,  the  leaf-crushers,  and  the  weeders  of  the  fungus 
garden,  in  busy  harmony,  for  this  magnificent  culture  of  fungi  destroy- 
ing the  forest.  They  are  so  numerous  that  they  give  the  life  of  the 
virgin  forests  of  South  America  a  peculiar  stamp.  At  every  step  you 
come  across  processions  of  leaf-carrying  ants  and  their  nests.  I  my- 
self was  able  in  a  short  trip  through  Colombia  to  corroborate  a  great 
part  of  the  beautiful  and  careful  scientific  discoveries  of  Professor 
Moller,  and  to  discover  the  as  yet  unknown  gardens  of  fungi  of  several 
species  and  genera.  Certain  Attini  have  a  rudimentary  instinct  of  horti- 
culture, and  merely  use  the  excrements  of  caterpillars,  wood  pulp,  etc. 
They  raise  another  fungus.  The  final  form  of  fungus  of  Rhozites  is  a 
large,  beautiful  agaric,  which  grows  on  the  nests  of  the  ants.  My 
attack  with  spades  on  a  nest  of  Atta  sexdens  L.,  one  metre  high  and 
six  metres  in  diameter,  turned  into  a  real  battle.  The  Indian  who 
helped  me  took  to  his  heels.  In  a  few  seconds  my  hands  bled  all  over 
from  the  sharp  bites  of  the  large  warriors.  But  I  succeeded  in  un- 
covering about  twenty  gardens  in  a  corner  of  the  nest.  Almost  every 
bite  of  a  warrior  bleeds.  The  natives  use  these  animals  for  suturing 
wounds  ;  they  have  the  ant  bite  together  the  two  wound  margins,  and 
then  they  sever  the  body  from  the  head.     The  head  remains  fastened  with 


442  Augrist  Forel : 

the  jaws,  and  closes  the  wound  like  a  small  forceps.  v.  Jhering  has 
shown  that  the  fertilized  females  of  Attini  carry  in  the  mouth  a  piece 
of  the  fungus  taken  from  the  nest.  In  this  manner  they  have  the 
germs  from  which  their  brood  raises  a  new  garden.  North  America  has 
a  small  horticultural  ant,  Atta  (Trachymyrmex)  Tardigrada  Buckley,  var. 
septentrionalis  McCook. 

The  habits  of  other  species  of  ants  were  well  known  to,  and  inter- 
preted by.  King  Solomon.  I  speak  of  the  subgenus  Messor,  which  lives 
in  masses  around  the  Mediterranean  Sea.  These  animals  also  make  large 
caves  in  the  ground.  They  collect  the  seeds  from  all  kinds  of  plants, 
and  accumulate  their  subterraneous  granaries.  There  they  know  how 
to  prevent  the  sprouting  until  it  is  convenient  for  them.  Then,  in  the 
moment  of  beginning  germination,  when  the  starch  changes  into  dias- 
tase and  sugar,  they  eat  the  grains,  both  in  summer  and  in  winter. 
There  are  no  real  winter  provisions,  as  Solomon  thought. 

In  Texas  there  is  an  ant  (^Pogonomyrmex  molefaciens}  which  allows  just 
one  kind  of  grass,  Aristida  oligantha,  to  grow  around  its  nest,  while  aU 
the  other  plants  are  weeded  out.  It  feeds  on  the  seeds,  and  is  the  famous 
agricultural  ant  of  Lincecum.  A  closely  related  form  (P.  barhatus) 
makes  peculiar  pavements  on  the  surface  of  its  nest  with  little  stones. 
Other  ants  (^Myrmecocystus  melliger  and  Mexicanus)  use  part  of  their 
workers  as  provision-pots.  These  ants  are  so  overfed  by  the  other 
workers  that  their  first  stomach  or  crop  reaches  the  size  of  a  wine-grape, 
and  correspondingly  distends  the  abdomen.  These  so-called  "nurses" 
cannot  walk  any  longer,  and  hang  in  the  subterraneous  spaces  as  pro- 
vision-pots for  the  community.  Types  of  this  kind  live  in  Mexico, 
Colorado,  and  Texas,  and  are  dug  out  and  eaten  by  children.  McCook 
has  studied  their  habits. 

A  topic  worthy  of  admiration  is  the  so-called  symbiosis  of  a  South 
American  ant,  Azteca  Mulleri,  with  the  Cecropia  tree  Imbanba  (  Cecropia 
peltata).  The  tree  is  hollow  inside.  On  peculiar  cushions  of  the 
shoulders  of  its  leaves  it  produces  granules  rich  in  albuminous  substance 
and  not  present  in  other  Cecropias  (MiiUer's  granules).  The  ant  lives 
in  the  hollow  space  of  the  Cecropia,  where  the  mother  of  the  colony  digs 
into  an  apparently  specially  adapted,  thinner  portion.  In  this  tree  the 
Azteca  finds  a  home  and  its  food  in  the  granules  of  Miiller.  But  it  is 
very  bellicose.  As  soon  as  the  leaf-cutting  ants,  just  mentioned,  attack 
the  Cecropia,  the  furious  Aztecas  defend  the  tree  and  throw  them  back. 


Biology  of  Ants.  443 

With  what  fury  the  Azteca  species  defend  their  trees  with  the  help  of  a 
very  odorous,  resinous  substance  secreted  by  the  anal  glands,  I  have  been 
able  to  see  repeatedly  in  Colombia,  where  some  live  in  self-made  pulp- 
nests,  hanging  on  the  branches  of  trees,  others  in  the  Cecropias  and  other 
hollow  trees,  and  one  even  under  the  flat  leaves  of  a  kind  of  ivy.  The 
symbiosis  of  Azteca  Mulleri  with  the  Cecropia  peltata  is,  however,  incom- 
plete, inasmuch  as  a  complete  mutual  dependence  of  the  two  organisms 
does  not  exist ;  the  Cecropia,  at  least,  can  live  without  the  ants,  at  least 
in  its  first  years.  But  the  symbiosis  of  the  fungus  Rhozites  gongylophora 
with  the  Atta  species  is  complete.  Neither  fungus  nor  ant  can  live  by 
itself ;  each  is  absolutely  dependent  on  the  other. 

The  ant  nests  have  their  parasites  and  domestic  animals  like  the  dwell- 
ings of  man.  Certain  lice  and  worms  trouble  the  ants,  and  lay  their 
eggs  into  their  brood.  There  also  exist  very  wonderful  relations  between 
certain  beetles,  lepismas,  centipedes,  etc.,  and  the  colonies  of  ants. 
They  are  called  guests,  although  as  a  rule  they  are  rather  harmful  lodgers 
for  the  ants.  They  are  tolerated  or  even  loved  by  the  ants  on  account  of 
a  certain  odor  or  pleasant  secretion  of  their  hairs,  which  the  ant  licks 
passionately.  They  live  as  members  of  the  colony  in  the  ant  nest,  and, 
as  Wasmann  has  so  well  described  and  Janet  corroborated,  take  the  habits 
of  ants.  They  are  fed  by  the  ants  from  mouth  to  mouth,  and  even 
feed  each  other.  They  communicate  by  means  of  their  feelers  with 
the  ants,  and  with  one  another.  Even  their  brood  is  usually  fed  and 
raised  mostly  by  the  ants  as  if  they  were  their  own.  Long  ago  I 
observed  the  feeding,  transportation,  and  nursing  of  the  larvae  of  Atemeles 
(a  beetle  living  with  the  ants),  and  wondered  why  the  ants  cared  for 
these  strangers  just  as  for  their  own  brood,  without,  however,  knowing 
then  that  these  larvse  belonged  to  the  same  beetle  which  is  a  guest  of  the 
ants  as  an  adult.  Wasmann  has  proved  this ;  he  also  has  demonstrated 
the  harmful  influence  of  these  guests  on  the  ant  colony  which  begins  to 
produce  pathological  malformations  between  the  worker  and  female, 
described  by  me  formerly  without  a  knowledge  of  the  cause. 

Other  guests  are  rather  mischievous  thieves,  which  creep  into  the 
nests  and  eat  the  ants  or  their  brood  (Myrmedonia)^  or  merely  in  order 
to  eat  the  excrements  of  ants  (Binarda).  The  excellent  biologist,  Was- 
mann, knew  that  in  migrations  of  a  colony  of  ants  to  a  new  nest  the 
whole  gang  of  little  guests  (beetles,  centipedes,  epismas)  know  how  to 
follow  the  ants  into  the  nest,  following  the  trace  by  their  sense  of  smell. 


444  August  Forel: 

I  myself  have  corroborated  this  observation.  This  is,  however,  not  the 
case  with  the  small,  round  TJiorictus  Foreli  living  in  the  nests  of  the  large 
and  long-legged  Myrmecoeystus  megalocola  in  Algeria.  It  is  too  small 
and  too  slow  to  be  able  to  follow  the  swift  ant.  Consequently  this  beetle 
(discovered  by  me  in  Algeria,  and  called  after  me  by  Wasmann)  always 
clings  to  the  shaft  of  the  feeler  of  the  ant,  and  is  carried  in  this  way.  A 
peciiliar  notch  in  the  head-shield  allows  it  to  wholly  embrace  with  its 
jaws  the  feeler  of  the  ant  without  hurting  it.  Lately  Wasmann  believed 
that  he  found  that  the  beetle  bores  a  hole  into  the  shaft  of  the  feeler  of 
the  ant  with  its  lower  jaws  and  suck  its  blood.  But  Escherich  denies 
this,  and  the  matter  is  not  settled. 

Even  more  remarkable  than  the  relations  of  these  guests  are  the 
slaves  and  the  friendly  relations  of  some  species  of  ants  to  one  another. 
Many  years  ago  I  accidentally  discovered  that  some  of  our  ants  (for 
instance,  Formica  rufa^  the  common  ant  of  our  forests),  which  usually 
live  by  themselves  and  work  hard,  in  very  exceptional  cases,  probably 
after  a  war  in  which  they  were  victorious,  let  the  chrysalides  of  other 
weaker  species  (Formica  fusca')  hatch,  rear  them,  and  consider  them  as 
members  of  their  community.  This  is  the  origin  of  the  rare  mixed 
colonies  which  give  the  explanatory  history  of  evolution  in  the  animal 
series  for  the  following  long-known  fact.  Charles  Darwin  had  theo- 
retically surmised  that  mode  of  origin  of  the  instinct  of  slavery  in  ants. 

The  Formica  sanguinea,  as  Huber  first  discovered,  is  almost  always  in 
the  habit  of  making  irregular  raids  in  June,  July,  and  August,  in  which 
they  surround  the  nests  of  Formica  fusca,  attack  this  weaker  species, 
and  chase  away  after  a  violent  struggle  the  inhabitants  of  the  nest,  whose 
brood  they  seize  and  carry  home.  The  larvse  and  chrysalides,  kidnapped 
in  this  manner,  hatch  in  the  nests  of  the  sanguviea,  where  they  feel  at 
home  very  much  as  kidnapped  infants.  There  they  render  the  greatest 
service  as  workers  to  the  robbers,  so  that  the  latter,  although  also  rela- 
tively active,  lead  an  easier  and  more  insolent  life  of  prey  than  their 
nearest  relations.  This  gives  the  Formica  sanguinea  a  very  peculiar, 
enterprising,  and  intelligent  biological  stamp.  It  is  taken  up  by  the 
daily  labor  much  less  than  other  species.  The  so-called  slaves,  or  better, 
helpers,  feel  themselves  so  well  at  home  that  they  do  not  recognize  their 
real  brothers  and  sisters  from  the  robbed  nest,  and  treat  them  as  enemies. 
It  is  established  that  the  ability  of  ants  to  recognize  begins  only  a  few 
days  after  the  hatching  of  the  chrysalis,  when  the  soft  chitine  is  getting 


Biology  of  Ants.  445 

harder.  In  order  to  show  this,  I  have  put  together  larvae  and  new-born 
ants  of  various  species  and  genera,  and  raised  a  mixed  but  peaceable 
colony.  In  North  America  there  are  families  of  Foi'mica  sanguinea 
(^ruhicunda  Emery,  etc.)  which  have  similar  habits. 

The  Amazon  ant  of  Huber  (^Polyergus  rufescens)  has  developed  fur- 
ther the  system  of  slaves.  Their  dagger-shaped,  bent  jaws  are  already 
unfit  for  work.  Like  a  Macedonian  phalanx,  its  rust-colored  army,  con- 
sisting of  usually  from  300  to  1200  ants,  rushes  from  its  nest  on  summer 
afternoons.  In  a  close  array  and  forced  march  it  follows  the  path  pre- 
viously reconnoitred  by  a  few  robbers,  and  in  one  half  to  one  hour  it 
covers  distances  of  from  fifty  to  one  hundred  metres.  It  is  true  the  army 
often  loses  its  way  or  stops  until  a  few  ants  have  found  it  again,  rapidly 
butt  with  their  heads  against  the  others,  and  give  them  the  sign  to  follow. 
If  not,  the  swarm  returns  unsuccessfully.  As  a  rule,  however,  they  reach 
a  nest  of  Formica  fusca  or  rufibarbus,  rush  with  an  incredible  haste  into 
the  entrances  of  the  nest,  and  sack  in  a  few  minutes  the  entire  brood  of 
the  unfortunate,  overpowered  ants  in  order  to  run  home,  and  to  throw  the 
prey  simply  to  their  helpers.  The  observation  of  such  an  expedition  is 
probably  the  most  interesting  zoological  spectacle  I  ever  have  witnessed. 
I  have  observed  them  very  often  in  the  canton  of  Vaud,  and  kept  statis- 
tics on  the  number  of  expeditions,  of  the  soldiers,  of  the  robbed  nests,  and 
the  rapidity  of  the  march.  The  Amazon  ant  completely  depends  on  its 
helpers.  Their  entire  brood  is  fed  and  cared  for  by  them.  Yea,  the 
robber  cannot  even  eat  without  help,  and  starves,  as  Huber  and  I  have 
shown,  in  presence  of  the  richest  food,  if  it  is  not  poured  into  its 
mouth  by  the  helpers.  It  is  able  to  swallow  if  its  mouth  happens  to  get 
into  honey  ;  but  the  instinct  to  eat  has  been  lost.  The  North  American 
Polyergus  lucidus  (which  robs  Formica  pallida  falva^  and  breviceps  have 
the  same  habits. 

The  little  genus  Strongylognathus  shows  how  the  instinct  of  robbing 
slaves  can  slowly  develop  into  parasitism.  In  1871,  I  discovered  a  new 
species  in  Wallis,  Strongylognathus  Huberi^  and  I  was  able  to  show  on 
the  spot  by  an  experiment  that  it  can  rob  like  Polyergus.  The  more 
frequent  and  smaller  Strongylognathus  testaceus,  however,  cannot  do  this 
any  longer.  This  small  and  weak  animal,  in  which  the  workers  are 
dying  out,  according  to  my  observations,  still  shows  ridiculous  remnants 
of  the  fighting  tactics  of  its  relatives.  Wasmann  has  proved  that  the 
fertilized   female   of    this   ant   sneaks   into   the    nests   of   another  kind. 


446  August  Forel : 

Tetramorium  ccespitum^  is  received  by  the  workers  beside  the  Tetramorium 
mother,  and  lives  beside  her.  For  some  cause  the  Tetramoriuras  raise 
from  that  time  on  the  workers  of  their  own  species  only ;  whereas  they 
allow  the  larvae  of  the  males  and  females  of  their  own  species  to  perish ; 
instead  of  this  they  raise  the  whole  brood  of  the  Strongylognathus  mother, 
perhaps  merely  since  it  causes  less  trouble  and  work. 

At  last  the  parasitism  of  the  Anergates  atratulus  goes  even  further, 
they  having  become  totally  devoid  of  workers.  Here  the  fertilized 
female  of  Tetramorium  ccespitum  is  received ;  whereas  the  own  mother 
of  the  colony  of  this  species  disappears  in  a  manner  not  yet  explained. 
As  long  as  the  existing  workers  live,  they  nurse  the  entire  brood  of  the 
Anergates  female,  consisting  merely  of  winged  females  and  wingless 
males.  The  Tetramorium  workers  from  that  time  merely  work  for  the 
parasites.  The  females  of  Anergates  are  fertilized  in  the  nest  by  their 
own  brothers  ;  not  till  then  do  they  fly  out  to  found  new  nests.  In 
this  manner  the  species  is  subject  to  continued  inbreeding,  since  there 
is  always  only  one  mother  in  a  nest ;  but  it  does  not  seem  to  suffer 
from  it.  In  North  America,  Epoecus  Pergandei  lives  as  a  parasite  with 
Monomorium  minutum.  But  nothing  definite  is  known  of  its  biology  as 
yet. 

Another  ant,  Formicoxenus  nitidulus  Nyl.,  lives  as  a  small  but  active 
tolerated  guest  with  its  entire  brood  in  the  partitions  of  the  nests  of  the 
common  wood  ant.     It  also  lives  in  the  Rocky  Mountains. 

The  northern  Tomognathus  suMcevis,  however,  according  to  Adlerz, 
penetrates  as  a  brutal,  uncalled-for  guest  into  the  nest  of  a  weaker  ant 
(^Leptothorax  acervorum},  and  forces  its  brood  on  these  animals,  more- 
over allowing  itself  to  be  lazy  and  comfortable  and  fed  by  the  host. 
The  wingless  worker  of  Tomognathus  is  at  the  same  time  female ;  the 
male  is  winged.  Tomognathus  Americanus  from  Washington  probably 
lives  in  a  similar  manner. 

The  tiny  but  warlike  Solenopsis  fugax  lives  in  very  small  rooms  and 
channels,  which  it  burrows  into  the  partitions  of  the  nests  of  larger  ants ; 
but  it  lives  there  as  an  enemy,  robber,  and  thief,  sneaking  among  the 
brood  of  the  larger  kind  and  eating  it  up.  Since  my  first  publication  of 
this  point  in  1869,  it  has  become  known  that  this  manner  of  living  occurs 
in  a  large  group  of  the  Solenopsis  species  and  related  genera,  such  as 
^romyrma,  certain  Monomorium  species,  etc.,  which  all  represent,  in  this 
manner,  small  robbers  hidden  in  the  walls  of  the  nests  of  larger  species. 


Biology  of  Ants.  447 

It  seems  that  in  North  America  Solenopsis  modera^  pollux,  and  molesta  live 
in  a  similar  manner.  In  Africa  and  India  the  Carehara  species  live  in  the 
same  way  in  the  nest  of  Termites,  also  .^hromyrma  in  Madagascar. 

In  the  Colombian  virgin  forests,  I  discovered  in  1896  a  new,  previ- 
ously unknown  relation  of  two  ant-colonies,  which  I  called  parabiosia. 
A  small  Dolichoderus  and  a  still  smaller  Cremastogaster,  both  of  a  deep 
black  and  glossy,  live  usually,  though  not  always,  together  in  the  follow- 
ing manner:  They  inhabit  the  same  nest,  probably  robbed  from  a  species 
of  Termites.  The  cavities  and  galleries  are  all  in  open  connection,  and 
are  inhabited  by  the  two  species  in  a  mix-up,  almost  inextricable  to  the 
human  eye.  This  much  is  certain,  that  the  two  species  do  not  mix.  Each 
occupies  definite  rooms  and  galleries,  and  cares  for  its  own  brood  only, 
notwithstanding  the  open  communication.  But  there  is  peace,  never 
war ;  in  common  expeditions,  the  two  species  leave  the  nest  in  order  to 
find  food  on  plants  and  trees,  but  only  to  the  point  where  the  final  aims 
divide ;  there  they  separate,  and  each  species  goes  on  to  its  special  aim 
(the  plant-lice  or  flowers).  Thus  we  have  a  peaceable  symbiosis  without 
mixing  and  without  any  intimate  relations.  The  relation  of  guests  might 
well  be  called  "Xenobiosis,"  the  helpers'  relation  "boethobiosis."  These 
expressions  would  be  preferable  not  only  among  ants,  but  also  for  analo- 
gous relations  of  other  animals.  Wasmann's  expressions  ("  Symphilie," 
etc.)  are,  however,  preferable.  Apart  from  the  raids  and  the  other  con- 
ditions described,  the  ant  colonies,  even  those  of  the  same  species,  have 
warfare  usually  about  the  source  of  nutrition.  We  men  believe  our- 
selves the  sovereigns  of  the  earth.  Obviously,  the  ants  do  the  same  in 
their  little  world,  since  the  larger  colony  considers  a  certain  district 
around  its  nest  as  its  property.  This  district  comprehends  trees,  plants, 
and  the  soil ;  whoever  enters  it  is  attacked,  and,  if  possible,  slain.  Hence 
the  wars  between  neighboring  colonies,  wars  which  are  often  carried  to 
the  annihilation  of  the  weaker  part.  A  victory  is  accounted  for  by  the 
number  and  courage  of  the  warriors,  and  also  by  certain  weapons,  as 
stings,  poison-sacks,  hardness  of  body,  swiftness,  resinous  secretions  of 
the  anal  glands  which  are  spurted  out,  certain  tricks,  as  for  instance  in 
Polyergus  the  piercing  of  the  brain  of  the  enemy,  in  Formica  exsecta  the 
sawing  off  of  the  neck,  or  the  like.  The  smaller  kinds  usually  take  hold 
of  the  legs  of  the  larger  ones,  seize  them  this  way,  and  finally  kill  them  by 
the  number  of  their  pricks  or  bites ;  whereas  the  big  ones  cut  or  crush  the 
small  with  their  jaws.     Whole  chains  of  combatants  are  formed,  of  which 


448  August  Forel : 

few  may  survive  the  battle.  Slowly  the  victor  gains  ground,  until  the 
enemy  either  faces  about  or  finally  is  surrounded  in  its  own  nest,  chased 
away,  or  killed  with  its  entire  brood.  Besides  such  larger  wars,  which 
may  last  days  or  weeks,  there  are  innumerable  skirmishes  along  the  fron- 
tiers, especially  about  the  possession  of  plant-lice. 

Yet  ants  do  not  merely  murder  and  carry  on  warfare  ;  they  also  can 
make  peace.  This  does  not  only  happen  because  two  exhausted  colonies 
often  give  up  fighting  and  avoid  a  certain  strip  of  contested  land,  but 
also,  in  rare  cases,  by  coalition  and  complete  union.  I  have  produced  this 
experimentally  by  mixing  rather  large  parts  of  nests  of  various  colonies  of 
Formica  fusca  with  their  inhabitants,  or  at  least  putting  them  close 
together  in  a  strange  place,  where  they  were  forced  to  build  a  new  nest. 
Necessity  and  circumstances,  the  mutual  need  for  food  and  habitation, 
reduced  the  warlike  impulses.  After  usually  insignificant  threats,  taunts, 
and  weak  attempts  at  fighting,  the  ants  began  to  work  together,  and  in 
the  course  of  one  or  two  days  formed  one  harmonious  colony.  If,  how- 
ever, you  bring  part  of  a  colony  near  the  nest  of  another  one,  it  is  driven 
away  and  often  annihilated. 

Once  (1871)  I  poured  the  inhabitants  of  two  colonies  of  very  hostile 
different  kinds  (^Formica  sanguinea  and  pratensis)  into  one  bag  and 
allowed  them  to  struggle  one  hour,  in  order  to  put  them  into  connection 
with  an  artificial  glass-nest.  Fighting,  with  the  greatest  excitement  and 
total  confusion,  the  ants  reached  the  glass-nest  where  they  carried  their 
larvae.  Necessity  gradually  reduced  the  fever  of  the  battle.  The  next 
day  several  hundred  had  killed  one  another  ;  the  survivors  began  to  work 
together,  though  defiant  and  threatening.  A  few  kept  up  the  fighting 
spirit.  After  five  days  the  union  was  perfect.  Ten  days  later  I  allowed 
them  to  get  out  on  the  meadow,  where  they  built  a  common  nest  and  after 
that  lived  in  undisturbed  friendship.  When,  however,  I  put  a  few  ants 
from  the  original  nest  of  the  pratensis  with  the  new  allies,  the  new  arrivals 
were  kindly  received  by  their  former  sisters,  but  fiercely  attacked  and 
partly  killed  by  the  sanguinea.  This  case  is  very  instructive,  and  shows 
that  the  sanguinea  had  closed  friendship  with  only  the  definite  set  of 
pratensis.,  and  were  quite  well  able  to  distinguish  them  from  the,  as  yet, 
unknown  sisters. 

The  instinctive  feeling  of  duty  of  the  workers  has  been  illustrated  by 
me  in  the  following  manner  :  One  meter  from  a  nest  of  Formica  pra- 
tensis^ I  placed  a  strong  portion  of  a  strange  colony  of  the  same  kind. 


Biology  of  Ants.  449 

Th^y  soon  began  the  attack,  and  a  great  battle  began,  lasting  several 
hours  and  costing  nearly  a  thousand  lives  on  the  two  sides.  While  the 
inhabitants  of  the  nest  rushed  out  to  the  defence  of  their  home,  I  poured 
honey  quite  close  to  the  soldiers  running  into  the  battle.  Under  ordi- 
nary circumstances  the  honey  would  have  become  black  with  ants  in  a 
short  time.  But  the  workers  passing  by  sipped  for  only  one  or  two 
seconds,  could  not  be  tempted  any  longer,  and  rushed  into  the  combat  — 
as  a  rule  into  death  —  although  the  ants  have  neither  criminal  law  nor 
court-martial.  Whoever  wants  to  be  a  coward  or  egoist  may  do  so  with- 
out any  interference.  But  the  ant  cannot  act  or  will  antisocially,  and 
this  is  the  secret  of  their  socialism.  In  the  struggle  between  the  individ- 
ual instincts  and  impulses  against  social  ones  the  latter  usually  have  the 
upper  hand.  There  are,  of  course,  short  hesitations  which  are  very  in- 
structive to  observe. 

As  has  been  said  already,  the  community  of  ants  realizes  the  purest 
ideals  of  our  modern  anarchists.  No  government,  no  king,  no  laws,  no 
bureaucracy,  no  officials.  Nobody  commands,  nobody  obeys.  Even  the 
so-called  slaves  are  perfectly  free  and  work  voluntarily,  from  mere  in- 
stinct. Hence,  absolute  freedom  with  absolute  solidarity.  When  a 
worker  wants  to  be  lazy,  he  is  cared  for  none  the  less  (this  is  seen  in  the 
Amazon  ant,  which  is  totally  dependent  on  its  "slaves").  But  this  laziness 
does  not  occur  at  all,  except  with  the  slave-makers  and  the  parasitic  species. 
Consequently  there  are  no  'cracies,  no  parties,  no  rebellions,  no  crimes ; 
at  least  almost  none  (and  we  must  remember  no  alcoholism  either) ;  at  the 
most  only  occasional  individual  differences  which,  however,  are  almost 
always  quite  short  and  insignificant. ^  And  yet,  there  is  the  most  perfect 
order,  indeed,  a  wonderful  skill  to  create  order  by  harmonious,  energetic 
work  in  a  short  time,  in  the  most  difficult  and  confused  situations  possible. 
If,  for  instance,  you  demolish  brutally  a  nest  of  ants,  take  all  the  inhabi- 
tants into  a  bag,  and  throw  them  in  a  completely  unknown  region  amidst 

1 1  have  described  one  exception  in  my  "Fourmis  de  la  Suisse"  ;  a  mixed  colony  of 
Amazon  ants  suffered  for  lack  of  food,  owing  to  prolonged  drought.  Then  I  saw  how  a  few 
helpers  (slaves),  importuned  for  food  by  the  Amazons,  would  bite  their  "masters,"  and 
finally  carry  them  as  far  as  possible  to  throw  them  away.  The  hard  Amazons  took  it  good- 
naturedly,  but  always  returned  home  at  once.  Tired  of  such  a  Sisyphus  labor,  one  of  the 
helpers  began  to  bite,  so  that  an  Amazon  lost  patience,  pierced  the  brain  of  the  rebellious  slave, 
and  thereby  killed  it  promptly.  This  fact  is  quoted  by  the  famous  criminal  anthropolo- 
gist, C.  Lombroso,  and  has  been  interpreted  as  a  case  of  crime  among  ants.  This  interpreta- 
tion stands  discussion,  and  the  case  is  certainly  instructive. 
2g 


450  August  Forel : 

enemies,  they  reconnoitre  rapidly,  gather  the  brood,  find  a  place  for  a 
nest,  hide  the  brood  provisionally  under  leaves  or  in  the  hole  of  a  cricket  ; 
the  enemies  are  kept  away,  the  nest  built,  food,  especially  plant-lice,  is 
sought  for  and  found,  etc. 

The  wonderful  and  manifold  social  instincts  of  ants  have  called  forth 
many  erroneous  views,  and  produced  a  sort  of  anthropomorphism  of  the 
ant's  mind.  There  are,  indeed,  enough  analogies  and  points  of  contact  be- 
tween the  society  of  man  and  of  ants, — slavery,  raising  of  cattle, horticulture, 
war,  treaties,  etc.  These  are  phenomena  of  convergence,  the  complicated 
connection  of  which  in  both  ant  and  man  is  brought  about  by  the  fact 
of  social  community  of  living  brains.  The  chief  difference  lies  in  the 
inherited  automatism  of  instinct  in  the  ant,  and  the  immensely  individual 
plasticity  of  the  human  brain.  You  may  ask  how  it  is  that  the  brain  of 
an  ant,  only  the  size  of  a  pin-head  (Charles  Darwin  calls  it  the  most  won- 
derful atom  of  substance  of  the  world),  can  do  as  complicated  things  as 
the  human  brain,  which  weighs  two  and  one-half  to  three  and  one-quarter 
pounds  ;  but  you  must  consider  the  other  side  of  the  matter,  namely,  the 
immense  limitation  of  an  ant  as  soon  as  it  ought  to  do  something  that 
does  not  lie  in  its  inherited  instinct.  We  see  the  Amazon  ant,  which  has 
such  complicated  ways  of  plundering,  perish  beside  ample  food  although 
it  can  lick  and  swallow,  because  it  has  lost  the  instinct  to  eat.  Every 
species  has  its  special  tricks,  but  only  those,  and  it  never  devises  anything 
else.  It  is  true,  that  ants  adapt  themselves  to  new  conditions  to  some 
extent,  and  better  than  other  insects,  because  their  brain  is  relatively  a 
little  larger  ;  but  this  is  the  case  only  in  a  very  limited  manner.  In  its 
whole  life,  an  ant  learns  almost  nothing  apart  from  a  certain  knowledge 
of  places,  and  the  ability  to  distinguish  other  ants ;  shortly  after  it  comes 
forth  from  its  chrysalis  it  knows  almost  all  it  will  ever  know,  innate  and 
inherited  ;  whereas  the  mammals,  and  even  the  birds,  learn  very  much 
during  their  lives,  have  far  more  memories,  and  combine  and  use  them. 
Hence,  it  follows  that  mental  or  cerebral  activities  which  are  one-sidedly 
complicated,  fixed  in  the  brain  and  inherited,  necessitate  far  fewer  brain 
elements  than  the  ability  to  learn  individually  to  combine,  to  adapt  itself, 
to  practise  new  activities,  and  to  make  them  become  secondarily  automatic 
by  practice.  This  ability,  which  may  be  called  plastic  in  comparison 
with  the  automatism  of  instinct,  especially  distinguishes  the  human  brain, 
although  even  we  think  and  feel  and  act  far  more  from  inheritance  than 
we  believe.     Still  there  is  no  actual  contrast  between  instinct  and  the 


Biology  of  Ants.  451 

plasticity  of  reason.  There  rather  are  thousands  of  transitions,  especially 
the  so-called  hereditary  dispositions,  which  are,  so  to  speak,  rudimentary, 
not  completely  developed  instincts,  and  which,  for  instance,  distinguish  a 
Mozart  or  a  Koszalzki,  who  were  able  to  become  virtuosi  and  composers 
as  children,  from  unmusical  persons  over  whom  all  the  teachers  labor  for 
years  in  vain. 

The  animals  with  complicated  high  instincts  are,  therefore,  by  no 
means  more  stupid  than  those  which  have  only  slight  instincts.  All 
depend  on  two  different  modalities  of  brain  activity  which  may  go,  side 
by  side,  to  a  varying  height,  without  excluding  one  another  mutually. 

As  I  wrote  over  twenty-five  years  ago,  the  community  of  ants  teaches 
us  further  that  the  social  state  of  man  cannot  be  arranged  after  the  pat- 
tern of  the  ants.  Man  has  too  much  and  too  little  for  this.  He  lacks 
the  sexless  workers,  the  social  first  stomach,  and,  above  all,  the  high  social 
instinct  which,  without  any  legal  compulsion,  works  much  rather  for  the 
community  than  for  itself.  In  return,  he  can  receive,  digest,  and  combine 
in  his  powerful  brain  a  world  of  plastic  concepts,  which  the  little  ant, 
with  her  automatic,  one-sided,  though  extremely  well-built  and  remarka- 
bly well-used,  brain  is  unable  to  do.  The  highly  developed  human  brain 
contains  an  unlimited  number  of  plastic  powers,  capable  of  development, 
connected  with  overpoweringly  strong  inherited  egoistic  instincts  and  pas- 
sions of  animals  of  prey,  but  capable  of  being  influenced  in  manifold 
manners  by  selections  and  by  individual  adaptations.  Man  and  his  brain 
cannot  be  forced  into  one  single  collective  or  anarchistic  dogma,  because 
overwhelming  impulses  lead  him  forcibly  toward  a  higher  evolution, 
which  cannot  be  defined  beforehand.  We  are,  of  course,  in  a  position  to 
recognize,  to  some  extent,  the  laws  of  this  psychical  evolution,  especially 
by  the  help  of  history,  of  ethnology,  of  psychology,  connected  with 
anatomy  and  physiology  of  the  brain,  and  to  remove,  in  a  negative  man- 
ner at  least,  that  which  deranges  and  inhibits  it,  as  the  use  of  alcohol,  of 
opium,  the  cult  of  the  golden  calf  and  of  illusory  gods,  and  other  causes 
of  degeneration,  and  to  try  positively  to  increase  the  number  of  the  fittest 
germs  at  the  expense  of  the  unfit.  But,  unfortunately,  the  higher  insight 
of  man  has  to  meet  continually  the  obstinate  narrowness  of  prejudice,  so 
that  the  victory  of  truth  is  not  easy. 

Notwithstanding  the  difference  of  their  physical  organizations  and 
size  from  ours,  with  all  their  relatively  low  rank  in  the  animal  series,  the 
ants,  with  their  social  biology  and  psychology,  are  an  extremely  valuable 


452  August  Forel :    Biology  of  Ants. 

and  interesting  object  of  comparison,  both  of  living  nature  and  of  the 
social  relations  of  man,  and  for  human  psychology  generally.  They 
prove  how  the  eternal,  divine  powers  of  nature  produce  equal  or  similar 
phenomena  in  completely  different  ways,  whether  they  be  those  of  living 
beings  in  their  various  combinations,  or  those  which  are  called  the  physico- 
chemical  powers  of  inorganic  and  organic  nature.  Have  not  slavery,  the 
raising  of  cattle,  and  horticulture  been  practised  by  ants  long  before  there 
were  any  men  on  earth  ?  These  ants  very  probably  have  acquired  these 
arts  in  the  way  of  natural  selection,  automatically,  in  the  course  of  innu- 
merable generations,  with  the  helps  of  inherited  combinations,  without 
there  ever  having  existed  an  ant  which  could  have  got  a  perspective  of 
the  adequacy  of  the  process,  individually.  Man,  however,  invents  indi- 
vidually, with  the  help  of  innumerable  combinations  of  plastic  impulses, 
and  he  often  devises,  individually,  things  which  long  before  had  been  pro- 
duced by  natural  powers,  or  living  beings  before  him.  Let  me  mention 
the  sail  long  used  by  the  nautilus,  electricity,  etc. 

In  Proverbs  vi.  6-8,  we  read :  "  Go  to  the  ant,  thou  sluggard ;  con- 
sider her  ways,  and  be  wise  ;  which  having  no  guide,  overseer,  or  ruler, 
provideth  her  meat  in  the  summer  and  gathereth  her  food  in  the  harvest." 
To  this  sentence,  which  is  scientifically  true,  word  for  word,  I  add  the 
following :  She  gives  man  the  social  doctrines  of  work,  of  harmony,  of 
courage,  of  sacrifice,  and  of  a  spirit  of  solidarity. 


DEGREES   CONFERHED. 


Following  are  the  degrees  conferred  by  the  University  during  its  first 
decade.  In  case  of  the  degree  of  Doctor  of  Philosophy,  the  subject  of 
the  dissertation  and  the  date  of  the  examination  are  given. 

DOCTORS   OF   PHILOSOPHY. 

MATHEMATICS. 
J.  W.  A.  Young,  Sept.  16,  1892. 

On  the  Determination  of  Groups  whose  Order  is  a  Power  of  a  Prime. 
American  Journal  of  Mathematics,  April,  1893,  Vol.  15,  pp.  124-178. 

William  H.  Metzlek,  Jan.  4,  1893. 

On  the  Roots  of  Matrices. 

American  Journal  of  Mathematics,  Oct.,  1892,  Vol.  14,  pp.  326-377. 

Thomas  F.  Holgate,  May  9, 1893. 

On  Certain  Ruled  Surfaces  of  the  Fourth  Order. 

American  Journal  of  Mathematics,  Oct.,  1893,  Vol.  15,  pp.  344-386. 

John  E.  Hill,  June  17,  1895. 

On  Quintic  Surfaces. 

Mathematical  Review,  July,  1896,  Vol.  1,  pp.  1-59. 

L.  Watland  Dowling,  June  19, 1895. 

On  the  Forms  of  Plane  Quintic  Curves. 

Mathematical  Review,  April,  1897,  Vol.  1,  pp.  97-119. 

Thomas  F.  Nichols,  June  20,  1895. 

On  Some  Special  Jacobians. 

Mathematical  Review,  July,  1896,  Vol.  1,  pp.  60-80. 

Warren  G-.  Bullard,  June  17,  1896. 

On  the  General  Classification  of  Plane  Quartic  Curves. 
Mathematical  Review,  Vol.  1,  pp.  193-208,  3  plates. 

Frederick  C.  Ferry,  June  15,  1898. 

Geometry  of  the  Cubic  Scroll  of  the  First  Kind. 

Archiv  for  Mathematik  og  Naturvidenskah,  B.  21,  Nr.  3. 

453 


454  Degrees  Conferred. 

Ernest  W.  Kettger,  June  16,  1898. 

On  Lie's  Theory  of  Continuous  Groups. 

American  Journal  of  Mathematics.     (In  press.) 

John  S.  French,  March  28,  1899. 

On  the  Theory  of  the  Pertingents  to  a  Plane  Curve.     (In  press.) 

PHYSICS. 
T.  Proctor  Hall,  June  19,  1893. 

New  Methods  of  Measuring  the  Surface-Tension  of  Liquids. 
Philosophical  Magazine,  Nov.,  1893,  Vol.  36,  pp.  385-413. 

Clarence  A.  Saunders,^  July  6,  1895. 

The  Velocity  of  Electric  Waves. 

Physical  Review,  Sept.-Oct.,  1896,  Vol.  4,  pp.  81-105. 

Thomas  W.  Edmondson,  July  11,  1896. 

On  the  Disruptive  Discharge  in  Air  and  Liquid  Dielectrics. 
Physical  Revieio,  Feb.,  1898,  Vol.  6,  pp.  65-97. 

Samuel  N.  Taylor,  July  31,  1896. 

A  Comparison  of  the  Electromotive  Force  of  the  Clark  and  Cadmium 
Cells. 
Physical  Review,  Sept.-Oct.,  1898,  Vol.  7,  pp.  149-170. 

Albert  P.  Wills,  June  21,  1897. 

On  the  Susceptibility  of  Diamagnetic  and  weakly  Magnetic  Substances. 
Physical  Review,  April,  1898,  Vol.  6,  pp.  223-238. 

William  P.  Botnton,  June  23,  1897. 

A  Quantitative  Study  of  the  High-Frequency  Induction  Coil. 
Physical  Review,  July,  1898,  Vol.  7,  pp.  35-63. 

CHEMISTRY. 
Thomas  H.  Clark,  June  13,  1892. 

The  Addition-Products  of  Benzo-  and  of  Toluquinone. 

American  Chemical  Journal,  Dec,  1892,  Vol.  14,  pp.  553-576. 

John  L.  Bridge,  Jan.  8,  1894. 

Ueber  die  Aether  des  Chinonoxims.     (p-Nitrosophenols.) 
Liebig's  Annalen,  Sept.,  1893,  Vol.  277,  pp.  79-104. 

Julius  B.  Weems,  June  20,  1894. 

On  Electrosyntheses  by  the  Direct  Union  of  Anions   of  Weak  Organic 
Acids. 
American  Chemical  Journal,  Dec,  1894,  Vol.  16,  pp.  569-588. 

1  Died  Dec.  19,  1898. 


Degrees  Conferred,  455 

BIOLOGY. 
Hermon  C.  Bumpus,  Sept.  29, 1891. 

The  Embryology  of  the  American  Lobster. 

Journal  of  Morphology,  Sept.,  1891,  Vol.  5,  pp.  215-262,  6  plates. 

William  M.  Wheeler,  May  10,  1892. 

A  Contribution  to  Insect  Embryology. 

Journal  of  Morphology,  April,  1893,  Vol.  8,  pp.  1-160,  6  plates. 

Edwin  0.  Jordan,  May  11,  1892. 

The  Habits  and  Development  of  the  Newt. 

Journal  of  Morphology,  May,  1893,  Vol.  8,  pp.  269-366,  5  plates. 

James  R.  Slonaker,  June  20,  1896. 

A  Comparative  Study  of  the  Area  of  Acute  Vision  in  Vertebrates. 
Journal  of  Morphology,  May,  1897,  Vol.  13,  pp.  445-502,  5  plates. 

Colin  C.  Stewart,  June  19,  1897. 

Variations  in  Daily  Activity  Produced  by  Alcohol  and  by  Changes  in 
Barometric  Pressure  and  Diet,  with  a  Description  of  Eecording  Methods. 
Journal  of  Physiology,  January,  1898,  Vol.  1,  pp.  40-56. 

PSYCHOLOGY. 
Herbert  Nichols,  Sept.  29,  1891. 

The  Psychology  of  Time,  Historically  and  Philosophically  Considered  with 
Extended  Experiments. 
American  Journal  of  Psychology,  Feb.,  1891,  Vol.  3,  pp.  453-529 ;  April, 
1891,  Vol.  4,  pp.  60-112. 

Alexander  F.  Chamberlain,  March  9,  1892. 

The  Language  of  the  Mississaga  Indians  of  Skugog.     A  Contribution  to 
the  Linguistics  of  the  Algonkian  Tribes  of  Canada. 
MacCalla  &  Co.,  Philadelphia,  1892.     84  pp. 

William  L.  Bryan,  Dec.  13,  1892. 

On  the  Development  of  Voluntary  Motor  Ability  —  with  a  Preface  on  the 
Requirements  of  Work  in  Experimental  Psychology. 
American  Jou.i'nal  of  Psychology,   Nov.,  1892,  Vol    5,   pp.   125-204,   3 
charts. 

Frederick  Tracy,  May  29,  1893. 

The  Psychology  of  Childhood. 

D.  C.  Heath  &  Co.,  Boston,  1893.     94  pp. 

Arthur  H.  Daniels,  June  21,  1893. 

The  New  Life :  A  Study  of  Regeneration. 

American  Journal  of  Psychology,  Oct.,  1893,  Vol.  6,  pp.  61-106. 


456  Degrees  Conferred. 

John  A.  Bergstrom,  May  14,  1894. 

An  Experimental  Study  of  Some  of  the  Conditions  of  Mental  Activity. 

American  Journal  of  Psychology,  Jan.,  1894,  Vol.  6,  pp.  247-274. 

Fletcher  B.  Dresslar,  June  14,  1894. 

Studies  in  the  Psychology  of  Touch. 

American  Journal  of  Psychology,  June,  1894,  Vol.  6,  pp.  313-368. 

Thaddeus  L.  Bolton,  April  30,  1895. 

Rhythm. 

American  Journal  of  Psychology,  Jan.,  1894,  Vol.  6,  pp.  145-238. 

Frank  Drew,  July  29,  1895. 

Attention :  Experimental  and  Critical. 

American  Journal  of  Psychology,  July,  1896,  Vol.  7.  pp.  533-573. 

James  H.  Leuba,  July  29,  1895. 

A  Study  in  the  Psychology  of  Religious  Phenomena. 

American  Journal  of  Psychology,  April,  1896,  Vol.  7,  pp.  309-385. 

Colin  A.  Scott,  June  30,  1896. 

Old  Age  and  Death. 

American  Joui-nal  of  Psychology,  Oct.,  1896,  Vol.  8,  pp.  67-122. 

Ellsworth  G.  Lancaster,  June  11,  1897. 

The  Psychology  and  Pedagogy  of  Adolescence. 

Pedagogical  Seminary,  July,  1897,  Vol.  5,  pp.  61-128. 

Ernest  H.  Lindley,  June  12,  1897. 

A  Study  of  Puzzles  with  Special  Reference  to  the  Psychology  of  Mental 
Adaptation. 
American  Journal  of  Psychology,  July,  1897,  Vol.  8,  pp.  431-493. 

A.  Caswell  Ellis,  June  18,  1897. 

The  History  of  the  Philosophy  of  Education.     (In  press.) 

George  E.  Dawson,  August  2,  1897. 

Psychic  Rudiments  and  Morality. 

American  Journal  of  Psychology.     (In  press.) 

Edwin  D.  Starbuck,  August  3,  1897. 

Some  Aspects  of  Religious  Growth. 

American  Journal  of  Psychology,  Oct.,  1897,  Vol.  9,  pp.  70-124. 

Frederic  Burk,  June  8,  1898. 

From  Fundamental  to  Accessory  in  the  Development  of  the  Nervous  Sys- 
tem and  of  Movements. 
Pedagogical  Seminary,  Oct.,  1898,  Vol.  6,  pp.  5-64. 

Linus  W.  Kline,  June  10,  1898. 

The  Migratory  Impulse  vs.  Love  of  Home. 

American  Journal  of  Psychology,  Oct.,  1898,  Vol.  10,  pp.  1-81. 


Degrees  Conferred.  457 

J.  Richard  Street,  June  11,  1898. 

A  Genetic  Study  of  Immortality. 

Pedagogical  Seminary,  Sept.,  1899,  Vol.  6,  pp.  267-313. 

Daniel  E.  Phillips,  June  13,  1898. 

The  Teaching  Instinct. 

Pedagogical  Seminary,  March,  1899,  Vol.  6,  pp.  188-245. 

Frederick  W.  Colegrove,  June  13,  1898. 

Individual  Memories. 

American  Journal  of  Psychology,  Jan.,  1899,  Vol.  10,  pp.  228-255. 

Henry  S.  Curtis,  June  16,  1898. 

Inhibition. 

Pedagogical  Seminary,  Oct.,  1898,  Vol.  6,  pp.  65-113. 

Frederick  E.  Bolton,  Aug.  15,  1898. 

Hydro-Psychoses. 

American  Journal  of  Psychology,  Jan.,  1899,  Vol.  10,  pp.  171-227. 

Henry  H.  Goddard,  June  12,  1899. 

The  Effects  of  Mind  on  Body  as  evidenced  by  Faith  Cures. 

American  Journal  of  Psychology,  April,  1899,  Vol.  10,  pp.  431-502. 

The  following  gentlemen  have  taken  the    examination   for   the  doctor's 
degree,  but  have  not  yet  completed  all  the  formal  requirements. 


Eugene  W.  Bohannon, 
Edmund  B.  Huey, 


Cephas  Guillet, 
George  E.  Partridge, 


Charles  H.  Walker. 


DOCTORS   OF   LAWS. 

HONORIS  CAUSA. 

LuDwiG  BoLTZMANN,  July  10,  1899. 

Professor  of  Theoretical  Physics,  University  of  Vienna. 

Santiago  Ramon  y  Cajal,  July  10,  1899. 

Professor  of  Histology,  and  Rector  of  the  University  of  Madrid. 

August  Forel,  July  10,  1899. 

Late  Director  of  the  Burgholzli  Asylum,  Switzerland. 

Angelo  Mosso,  July  10,  1899. 

Professor  of  Physiology,  and  Rector  of  the  University  of  Turin. 

i^MiLE  PicARD,  July  10,  1899. 

Professor  of  Mathematics,  University  of  Paris. 


TITLES   OF   PAPERS 

Published  by  Past  and  Present  Members  of  the  Staff, 
Fellows,  and  Scholars. 


H.   AUSTIN   AIKINS:  — 

B.A.,  University  of  Toronto,  1887  ;  In- 
structor, University  of  Southern  Cali- 
fornia, 1888 ;  Graduate  Student,  Yale 
University,  1888-91  ;  Lecturer  on  History 
of  Philosophy,  ibid.,  1890-91  ;  Ph.D., 
Yale  University,  1891  ;  Professor  of  Logic 
and  Philosophy,  Trinity  College,  North 
Carolina,  1891-92  ;  Fellow  in  Psychol- 
ogy, Clark  University,  Oct.,  1892- 
Jan.,  1894  ;  Professor  of  Philosophy, 
.  College  for  Women,  Western  Reserve 
University,  Cleveland,  O.,  Jan.,  1894-. 

Author  of :  — 

The  Philosophy  of  Hume,  in  extracts,  vrith 
Introduction.  (Sneath's  Series  of  Mod- 
ern Philosophers.)  Henry  Holt  &  Co., 
N.  Y.,  1893.     176  pp. 

From  the  Reports  of  the  Plato  Club.  At- 
lantic Monthly,  Sept.  and  Oct.,  1894, 
Vol.  74,  pp.  359-368  ;  470-480. 

The  Daily  Life  of  a  Protozoan  (vrith  C.  F. 
Hodge).  Am.  Jour,  of  Psy.,  Jan., 
1895,  Vol.  6,  pp.  524-533. 

Education  of  the  Deaf  and  Dumb.  Edu- 
cational Beview,  Oct.,  1896,  Vol.  12, 
pp.  236-251. 

The  Field  of  Pedagogy.  Western  Reserve 
University  Bulletin,  April,  1897,  Vol. 
3,  pp.  15-21. 

R.    AKIYAMA:  — 

School  of  Science,  Tokio,  Japan,  1888- 
90 ;  College  of  Pharmacy,  San  Fran- 
cisco, Cal,,  1890-91  ;  Student  in  Chem- 
istry, University  of  California,  1891-93  ; 


Scholar  in  Chemistry,  Clark  Univer- 
sity, 1893-94. 

ERNEST   ALBEE:  — 

A.B.,  University  of  Vermont,  1887 ; 
Scholar  in  Philosophy,  Clark  Univer- 
sity, 1889-90  ;  Fellow  in  Philosophy, 

1890-91  ;  Fellow  Sage  School  of  Phi- 
losophy, Cornell  University,  1891-92  ; 
Instructor  in  Philosophy,  ibid.,  1892- ; 
Ph.D.,  Cornell  University,  1894  ;  Mem- 
ber of  the  Am.  Psy.  Ass'n. 

Author  of :  — 

The  Ethical  System  of  Richard  Cumber- 
land. Philosophical  Beview,  May  and 
July,  1895,  Vol.  4,  pp.  264-290  ;  371- 
393. 

The  Relation  of  Shaftesbury  and  Hutche- 
son  to  Utilitarianism.      Ibid.,   Jan., 

1896,  Vol.  5,  pp.  24-35. 

Gay's   Ethical    System.      Ibid.,  March, 

1897,  Vol.  6,  pp.  132-145. 

Hume's  Ethical  System.  Ibid.,  July, 
1897,  Vol.  6,  pp.  337-355. 

ARTHUR  ALLIN:  — 

A.B.,  Victoria  University,  Toronto,  1892 
(Double  Gold  Medalist  in  Classics  and 
Philosophy)  ;  University  of  Heidelberg, 
1892  ;  University  of  Breslau,  1892-93 ; 
Ph.D.,  Berlin  University,  1895;  Hono- 
rary Fellow  in  Philosophy,  Clark 
University,  1895-96 ;  Professor  of  Psy- 
chology and  Education,  Ohio  University, 
1896-97  ;  Professor  of  Psychology  and 
Education,  University  of  Colorado,  1897-  ; 


459 


460 


Titles  of 


Consulting  Psychologist,  State  Industrial 
School  of  Colorado. 

Author  of ;  — 

Ueber  das  Grundprincip  der  Association, 

BerUn,  1895. 
The  Recognition-Theory  of    Perception. 

Am.  Jour,  of  Psy.,  Jan.,  1896,  Vol.  7, 

pp.  237-248. 
Recognition.     Ibid.,   Jan.,    1896,  Vol.  7, 

pp.  249-273. 
The  Psychology  of   Tickling,   Laughing, 

and  the  Comic  (with  G.  S.  Hall).  Ibid., 

Oct.,  1897,  Vol.  9,  pp.  1-41. 
Pedagogy  in  Ohio.     Trans.  Ohio  College 

Ass'n,  1897. 
ExtrarOrganic  Evolution.     Science,  Feb. 

25,  1898,  N.  S.,  Vol.  7,  pp.  267-269. 
Extra-Organic  Evolution  and  Education, 

Northwestern  Monthly,  May  and  June, 

1899,  Vol.  9,  pp. 400-403;  436-439. 

LOUIS   "W.   AUSTIN:  — 

A.B.,  Middlebury  College,  1889;  Stu- 
dent, University  of  Strassburg,  1889-90 
and  1891-93  ;  Fellow  in  Physics,  Clark 
University,  1890-91 ;  Ph.D.,  University 
of  Strassburg,  1893  ;  Instructor  in  Physics, 
University  of  Wisconsin,  1893-96  ;  Assist- 
ant Prof  essor,  ibid.,  1896-  ;  Member  of  the 
"Wisconsin  Academy  of  Sciences. 

Author  of  :  — 

Experimentaluntersuchungen  iiber  die 
elastische  Langs-  und  Torsionsnach- 
wirkung  in  Metallen.  Annalen  der 
Fhysik  und  Chemie,  1893,  N.  F.,  Bd. 
50,  pp.  659-677. 

The  Effect  of  Extreme  Cold  on  Magnet- 
ism. Physical  Beviexo,  March-April, 
1894,  Vol.  1.,  pp.  381-382. 

An  Experimental  Research  on  the  Lon- 
gitudinal and  Torsional  Elastic  Fa- 
tigue. Ibid.,  May-June,  1894,  pp. 
401-4-25. 

On  Gravitational  Permeability.  (With 
Charles  B.  Thvping. )  Ibid. ,  Nov.-Dec. , 
1897,  Vol.  5.,  pp.  294-300. 

Exercises  in  Physical  Measurement. 
(With  Charles  B.  Thwing.)  Allyn 
and  Bacon,  Boston,  1896.     208  pp. 


N.    P.    AVERY:  — 

A.B.,  Amherst  College,  1891 ;  Principal, 
Yates  Academy,  Chittenango,  N.  Y.,  1891- 
95  ;  Scholar  in  Psychology,  Clark  Uni- 
versity, Oct.,  1895-Jan.,  1896;  ad- 
mitted to  the  Massachusetts  bar,  June, 
1896. 

FRANK  K.  BAILEY  :  — 

S.  B.,  Colorado  College,  1898  ;  Scholar  in 
Physics,  Clark  University,  1898-99. 

THOMAS   P.    BAILEY,  JR.:  — 

A.B.,  South  Carolina  College,  1887  ; 
Principal  Wiuyah  School,  Georgetovyn, 
S.  C,  1887-88;  Tutor  in  English  and 
History,  University  of  South  Carolina, 
1888-89 ;  A.M.,  University  of  South 
Carolina,  1889  ;  Secretary,  ibid.,  1889-91  ; 
Ph.D.^  University  of  South  Carolina, 
1891  ;  Adjunct  Professor  of  Biology, 
South  Carolina  College,  1891-92  ;  Fellow 
in  Psychology,  Clark  University, 
1892-93  ;  Lecturer,  South  Carolina  Col- 
lege for  Women,  1893-94 ;  Superinten- 
dent of  Schools,  Marion,  S.  C,  1894-95; 
Assistant  Professor  of  Science  and  Art  of 
Teaching,  University  of  California,  1894- 
98 ;  Associate  Professor  of  Education  as 
related  to  Character,  ibid. ,  1898-. 

Author  of :  — 

The  Development  of  Character  (Doctor's 

Thesis),  1891. 
Humanity  of  the  Spiritual  Life.    Christian 

Thought,  Oct.,  1892. 
Ejective  Philosophy.     Am.  Jour,  of  Psy., 

July,  1893,  Vol.  5,  pp.  465-471. 
Herbart  and  Character  Culture.     So.  Ed. 

Jour.  Dec.  1893-Jan.  1894. 
Psychology  for  Teachers.      Proc.   S.   C. 

Teachers''  Ass''n,  1893. 
The  Practice  of  Medicine  and  the  Practice 

of  Teaching.     Ibid.,  1894. 
Comparative    Child-study    Observations. 

Handbook  III.   Soc.  for   Child-study, 

1895. 
The  Teaching  Force  —  its  General  Culture. 

Proc.  Cal.  Teachers'  Ass'n,  1894. 
Child-study   for   "Naturalists."      Pacific 

Ed.  Jour.,  April-May,  1895. 


Published  Papers. 


461 


The  Education  of  the  Human  Animal. 

Proc.  Cal.  Teachers'  Ass'n,  1896. 
Adolescence.     Ibid.,     1896. 
Child-study  Notes.        Overland  Monthly 

(School  Edition),  1896-97. 
Work  and  Play.     Proc.  Cal.    Teachers' 

Ass'n,  1896. 
Ethological  Outlines.    Oakland  School  Be- 

port,  1896-97. 
Ethology  and  Child-study.    Northwestern 

Monthly,  Nov.,  1897,  Jan.,  1898. 
Ethology  and  Child-study.     Proc.  S.  Cal. 

Teachers'  Ass'n,  1898. 
Reformers  in  Ethology.     Bui.   No.    13, 

Library  Univ.  of  Cal.,  1899. 
Ethology  :  Standpoint,  Method,  Tentative 

Results.     University   Chronicle    (Uni- 
versity   of    California),    Dec,    1898, 

Feb.,  1899. 

HENR7   ROLFE  BAKER:  — 

A.B.,  Iowa  College,  1882;  A.M.,  1885; 
B.D.,  Yale  University,  1886;  Congrega- 
tional Ministry,  1887  ;  Graduate  Student, 
Andover  Theological  Seminary,  1889-90  ; 
Hopkins  Graduate  Student  in  Philosophy 
and  Comparative  Religion,  Harvard  Di- 
vinity School,  1890-91 ;  Student  in 
Psychology,  Clark  University,  1894- 
95 ;  Fellow,  1895-97 ;  Honorary 
Fellow,  1898-99. 

Author  of :  — 

The  Position  of  Myth,  Science,  and  Na- 
ture Study  in  the  Philosophy  of  Edu- 
cation. 

FRANKLIN   W.    BARROWS: 

A.B.,  Amherst  College,  1885;  Instructor 
in  Sciences,  Worcester  Academy,  1885-88 ; 
A.M.,  Amherst  College,  1888  ;  Instructor 
in  Natural  Sciences,  Central  High  School, 
Buffalo,  N.  Y.,  1888-Jan.  1894;  M.D., 
University  of  Buffalo,  189.3  ;  Fellow  in 
Physiology,  Clark  University,  Jan.- 
June,  1894  ;  Instructor  in  Zoology  and 
Physiology,  Central  High  School,  Buf- 
falo, N.  Y.,  1894  ;  Instructor  in  Histology 
and  Biology,  Medical  Department  of  Uni- 
versity of  Buffalo,  1894-97 ;  Professor, 
ibid.,  1897-. 


GEORGE  H.   C.  L.  BAUR  : — 

Academy  of  Hohenheim,  1878-79 ;  Uni- 
versity of  Munich,  1879-81  ;  University 
of  Leipzig,  1881-82  ;  Ph.D.,  University 
of  Munich,  1882  ;  Assistant  to  Professor 
C.  Kupffer,  Munich,  1882-84 ;  Assistant 
to  Professor  O.  C.  Marsh,  Yale  Univer- 
sity, 1884-90 ;  Docent  in  Osteology 
and  Paleontology,  Clark  University, 
1890-92  ;  In  charge  of  the  Salisbury  Ex- 
pedition to  the  Galapagos  Islands,  May- 
Oct,  1891  ;  Assistant  Professor,  Osteology 
and  Paleontology,  University  of  Chicago, 
1892-95  ;  Associate  Professor,  ibid.,  1895- 
97. 
Died  June  25,  1898. 

Author  of :  — 

Der  Tarsus  der  Vogel  und  Dinosaurier. 
Eine  Morphologische  Studie.  Inau- 
gural-dissertation. Univers.  Miinchen. 
Leipzig,  1882,  Wilh.  Engelmann,  pp. 
1-44,  2  taf.  Same  in  Moiph.  Jahrb., 
1883,  Bd.  8,  pp.  417-456,  Taf.  XIX. 
and  XX. 

Der  Carpus  der  Paarhufer.  Eine  Mor- 
phogenetische  Studie.  (Vorl.  Mittheil.) 
Morph.  Jahrb.,  1884,  Bd.  9,  pp.  597- 
603. 

Dinosaurier  und  Vogel.  Eine  Erwieder- 
ung  an  Herrn.  Prof.  W.  Dames  in 
Berlin.  Ibid.,  1885,  Bd.  10,  pp.  446- 
454. 

Note  on  the  Pelvis  in  Birds  and  Dinosaurs. 
American  Naturalist,  Dec,  1884,  Vol. 

18,  pp.  1273-1275. 

Bemerkungen  iiber  das  Becken  der  Vogel 

und    Dinosaurier.       3Iorph.     Jahrb., 

1885,  Bd.  10,  pp.  613-616. 
Zur  Morphologic  des  Tarsus  der  Sauge- 

thiere.    Ibid.,  1885,  Bd.  10,  pp.  458- 

461. 
On  the  Morphology  of  the  Tarsus  in  the 

Mammals.  American  Naturalist,  Jan., 

1885,  Vol.  19,  pp.  86-88. 
Ueber  das  Centrale  Carpi  der  Saugethiere. 

Morph.  Jahrb.,  1885,  Bd.  10,  pp.  455- 

457. 
On  the  Centrale  Carpi  of  the  Mammals. 

American  Naturalist,  Feb.,  1885,  Vol. 

19,  pp.  195-196. 


462 


Titles  of 


Das  Trapezium  der  Cameliden.     Morph. 

Jahrb.,  1885,  Bd.  10,  pp.  117-118. 
The  Trapezium  of  tlie  Camel  idse.    Ameri- 
can Naturalist,  Feb.,  1895,  Vol.  19,  pp. 

196-197. 
A  Second  Phalanx  in  the  Third  Digit  of 

a  Carinate-Bird's  Wing.    Science,  May 

1,  1885,  Vol.  5,  p.  355. 
A  Complete  Fibula   in   an   Adult  Living 

Carinate-Bird.      Ibid.,  May  8,    1885, 

Vol.  6,  p.  375. 
On  the   Morphology  of  the  Carpus  and 

Tarsus    of     Vertebrates.      American 

Naturalist,  July,    1885,   Vol.   19,  pp. 

718-720. 
Zur  Morphologie  des  Carpus  und  Tarsus 

der  Wirbelthiere.     Zool.  Anz.,  1885, 

No.  196,  pp.  326-329. 
Zur  Vogel-Dinosaurier-Frage.  Ihid.,  1885, 

No.  200,  pp.  441-443. 
Nachtragliche  Bemerkungen  zu  :  Zur  Mor- 
phologie des  Carpus  und  Tarsus  der 

Wirbelthiere    {Zool.  Anz.,   1885,  No. 

196).     Ibid.,  1885,  No.  202,  pp.  486- 

488. 
Zum  Tarsus  der  Vdgel.    Ibid.,  1885,  No. 

202,  p.  488. 
Note  on  the  Sternal  Apparatus  in  Iguano- 

don.     Ibid. ,  1885,  No.  205,  pp.  561-562, 
Einige  Bemerkungen  liber  die  Ossification 

der  "laugen"  Knochen.     Ibid.,  1885, 

No.  206,  pp.  580-581. 
Bemerkungen  iiber  den  ' '  Astralagus ' '  und 

das  ' '  Intermedium  tarsi ' '  der  Sauge- 

thiere.     Morph.  Jahrb.,  1886,  Bd.  11, 

pp.  468-483,  Taf.  XXVII. 
Zur  Morphologie  des  Carpus  und  Tarsus 

der  Reptilien.    (Vorl.  Mittheil.)    Zool. 

Anz.,  1885,  No.  208,  pp.  631-639. 
Ueber  das  Archipterygium  und  die  Ent- 

wicklung  des  Cheiropterygium  aus  dem 

Ichthyopterygium.      (Vorl.   Mittheil.) 

Ibid.,  1885,  No.  209,  pp.  663-666. 
Preliminary  Note  on  the  Origin  of  Limbs. 

American  Naturalist,  Nov.  1885,  Vol. 

19,  p.  1112. 
Historische      Bemerkungen.       Internat. 

Monatschr.   f.   Anat.  u.    Hist.,  1886, 

Bd.  3,  pp.  3-7. 
Der  alteste  Tarsus  ( Archegosaurus) .  Zool. 

Anz.,  1886,  No.  216,  pp.  104-106. 


The  Oldest  Tarsus  (Archegosaurus). 
American  Naturalist,  Feb.,  1886,  Vol. 
20,  pp.  173-174. 

W.  K.  Parker's  Bemerkungen  iiber  Ar- 
chaeopteryx,  1864,  und  eine  Zusam- 
menstellung  der  hauptsachlichsten 
Litteratur  iiber  diesen  Vogel.  Zool. 
Anz.,  1886,  No.  216,  pp.  106-109. 

The  Intercentrum  of  Living  Reptilia. 
American  Naturalist,  Feb.,  1886,  Vol. 
20,  pp.  174-175. 

The  Proatlas,  Atlas  and  Axis  of  the  Cro- 
codilia.  Ibid.,  March,  1886,  Vol.  20, 
pp.  288-293,  5  figs. 

Die  zwei  Centralia  im  Carpus  von  Sphe- 
nodon  (Hatteria)  und  die  Wirbel  von 
Sphenodon  und  Gecko  verticillatus 
Laur  (G.  verus  Gray).  Zool.  Anz., 
1886,  No.  219,  pp.  188-190. 

Herrn  Prof.  K.  Bardeleben's  Bemerkungen 
iiber  "Centetes  madagascariensis. " 
Ibid.,  1886,  No.  220,  pp.  219-220. 

Ueber  die  Kanale  im  Humerus  der  Am- 
nioten.  Morph.  Jahrb.,  Bd.  12,  pp. 
299-305. 

Bemerkungen  iiber  Sauropterygia  und 
Ichthyopterygia.  Zool.  Anz.,  1887, 
No.  221,  pp.  245-252. 

Ueber  das  Quadratum  der  Saugethiere. 
Sitzungsber.  Gesell.  Morph.  u.  Phys- 
iol., Miinchen,  1886,  pp.  45-57. 

On  the  Quadrate  in  the  Mammalia. 
Quart.  Jour.  Micr.  Sci.,  1886,  Vol.  28, 
new  ser.,  pp.  169-180. 

Ueber  die  Morphogenie  der  Wirbelsaule 
der  Amnioten.  Biol.  Centralbl.,  1886, 
Bd.  6,  Nos.  11,  12,  pp.  332-342,  353-363. 

The  Intercentrum  in  Sphenodon  (Hat- 
teria). American  Naturalist,  May, 
1886,  Vol.  20,  pp.  465-466. 

Berichtigung.  Zool.  Anz.,  1886,  No.  223, 
p.  323. 

The  Ribs  of  Sphenodon  (Hatteria). 
American  Naturalist,  "Noy.,  1886,  Vol. 
20,  pp.  979-981. 

Ueber  die  Homologien  einiger  Schadel- 
knochen  der  Stegocephalen  und  Rep- 
tilien. Anat.  Anz.,  1886,  Jahrg.  1, 
pp.  348-350. 

Osteologische  Notizen  iiber  Reptilien. 
Zool.  Anz.,  1886,  No.  238,  pp.  685-690. 


Published  Papers. 


463 


Osteologische  Notizen  iiber  Reptilien. 
Fortsetzung  I.  Ihid.,  1886,  No.  240, 
pp.  733-743. 

On  the  Morphogeny  of  the  Carapace  of 
the  Testudinata.  American  Natural- 
ist, Jan.,  1887,  Vol.  21,  p.  89. 

Osteologische  Notizen  liber  Reptilien. 
Forsetzung  II.  Zool.  Anz.,  1887,  No. 
244,  pp.  96-102. 

Erwiedermig  an  Herrn  Dr.  A.  Giinther. 
Ibid.,  1887,  No.  245,  pp.  120-121. 

Ueber  Lepidosiren  paradoxa  Fitzinger. 
Zool.  Jahrb.,  1887,  Bd.  2,  pp.  575-583. 

Nachtragliche  Notiz  zu  meinen  Bemer- 
kungen :  "  Ueber  die  Homologien 
einiger  Schadelknochen  der  Stegoceph- 
alen  und  Reptilien"  in  No.  13  des 
ersten  Jahrgangs  dieser  Zeitschrift. 
Anat.  Anz.,  1887,  Jahrg.  2,  No.  21, 
pp.  657-658. 

On  the  Phylogenetic  Arrangement  of  the 
Sauropsida.  Jour,  of  Morph.,  Sept., 
1887,  Vol.  1,  pp.  93-104. 

Ueber  die  Abstammung  der  Amnioten 
Wirbelthiere.  Biol.  Centralbl,  1887, 
Bd.  7,  No.  16,  pp.  481-493. 

On  the  Morphology  and  Origin  of  the 
Ichthyopterygia.  American  Natural- 
ist, Sept.,  1887,  Vol.  21,  pp.  837-840. 

On  the  Morphology  of  Ribs.     Ibid.,  Oct., 

1887,  Vol.  21,  pp.  942-945. 
Beitrage  zur  Morphogenie  des  Carpus  und 

Tarsus    der    Vetebraten.       1     Theil. 
Batrachia.      Jena,     Gustav    Fischer, 

1888,  pp.  1-86,  Taf.  I.-III. 

Ueber  den   Ursprung  der  Extremitaten 

der    Ichthyopterygia.      Bericht.    uber 

die  SO.  Versam.  d.  Oberrhein.  Geolog. 

Vereins,  Jan.  16,  1888,  4  pp.,  1  taf. 
Dermochelys,  Dermatochelys  oder  Sphar- 

gis.     Zool.  Anz.,  1888,   No.  270,  pp. 

44-45. 
Unusual  Dermal  Ossifications.     Science, 

March  23,  1888,  Vol.  11,  p.  144. 
Notes    on    the    American    Trionychidse. 

American  Naturalist,  Dec,  1888,  Vol. 

22,  pp.  1121-1122. 
The  Theory  of  the  Origin  of  Species  by 

Natural  Selection.    Ibid.,  Dec,  1888, 

Vol.  22,  p.  1144. 
Osteologische    Notizen    iiber    Reptilien. 


Fortsetzung  III.  Zool.  Anz.,  1888,  No. 
285,  pp.  417-424. 

Osteologische  Notizen  iiber  Reptilien. 
Fortsetzung  IV.  Ibid.,  1888,  No.  291, 
pp.  592-597. 

Osteologische  Notizen  iiber  Reptilien. 
Fortsetzung  V.  Ibid.,  1888,  No.  296, 
pp.  736-740. 

Osteologische  Notizen  iiber  Reptilien, 
Fortsetzung  VI.  Ibid.,  1889,  No.  298, 
pp.  40-47. 

Revision  meiner  Mittheilungen  im  zool- 
ogischen  Anzieger,  mit  Nachtragen. 
Ibid.,  1889,  No.  306,  pp.  238-243. 

Neue  Beitrage  zur  Morphologie  des  Carpus 
der  Saugethiere.  Anat.  Anz.,  1889, 
Jahrg.  4,  No.  2,  pp.  49-51,  4  figs. 

The  Systematic  Position  of  Meiolania, 
Owen.  Ann.  Mag.  Nat.  Hist.,  (6) 
Jan.,  1889,  Vol.  3,  pp.  54-62. 

On  "  Aulacochelys,"  Lydekker,  and  the 
Systematic  Position  of  Anosteira,  and 
Pseudotrionyx,  DoUo.  Ibid.,  1889,  (6) 
Vol.  3,  pp.  273-276. 

On  Meiolania  and  Some  Points  in  the 
Osteology  of  the  Testudinata :  a  Reply 
to  Mr.  G.  A.  Boulenger.  Ibid.,  1889, 
(6)  Vol.  4,  pp.  37-45,  PI.  vi. 

Mr.  E.  T.  Newton  on  Pterosauria.  Ibid., 
1889,  pp.  171-174. 

Die  systematische  Stellung  von  Dermo- 
chelys Blainv.  Biol.  Centralbl.,  1889, 
Bd.  9,  Nos,  5  und  6,  pp.  149-153,  180- 
191. 

Nachtragliche  Bemerkungen  iiber  die  sys- 
tematische Stellung  von  Dermochelys 
Blainv.  Ibid. ,  1889,  Bd,  9,  Nos.  20  und 
21,  pp.  618-619. 

Palaeohatteria  Credner  and  the  Progano- 
sauria.  Am.  Jour,  of  Sci.,  April,  1889, 
Vol.  37,  pp.  310-313. 

Kadaliosaurus  prisons  Credner,  a  new 
Reptile  from  the  Lower  Permian  of 
Saxony.  Ibid.,  Feb.,  1890,  pp.  156- 
158, 

Bemerkungen  iiber  den  Carpus  der  Pro- 
boscidier  und  der  Ungulaten  im  Alge- 
meinen,  Morph.  Jahrb.,  1889,  Bd.  15, 
Heft  3,  pp.  478-482,  1  fig. 

On  the  Morphology  of  Ribs  and  the  Fate 
of  the  Actinosts  of  the  Median  Fins  in 


464 


Titles  of 


Fishes.  Jour,  of  Morph.,  Dec,  1889, 
Vol.  3,  pp.  4G3-4GG,  7  figs. 

On  the  Morphology  of  the  Vertebrate- 
Skull.  Ibid.,  1889,  Vol.  3,  No.  3,  pp. 
467-474. 

A  Review  of  the  Charges  against  the 
Paleontological  Department  of  the 
U.  S.  Geological  Survey,  and  of 
the  Defence  made  by  Prof.  O.  C. 
Marsh.  American  Naturalist,  March 
26,  1890,  Vol.  24,  pp.  298-304. 

Note  on  Carettochelys,  Ramsay.  Ibid., 
Nov.,  1889,  Vol.  23,  p.  1017. 

The  Gigantic  Land  Tortoises  of  the  Gala- 
pagos Islands.  Ibid.,  Dec,  1889,  Vol. 
23,  pp.  1039-1057. 

The  Relationship  of  the  Genus  Dirochelys. 
Ibid.,  Dec,  1889,  Vol.  23,  pp.  1099- 
1100. 

The  Genera  of  the  Podocnemididse.  Ibid., 
May,  1890,  Vol.  24,  pp.  482-484. 

Note  on  the  Genera  Hydraspis  and  Rhine- 
mys.  Ibid.,  May,  1890,  Vol.  24,  pp. 
484-485. 

The  Genera  of  the  Cheloniidae.  Ibid., 
May,  1890,  Vol.  24,  pp.  486-487. 

On  the  Classification  of  the  Testudinata. 
Ibid.,  June,  1890,  Vol.  24,  pp.  530- 
536. 

Professor  Marsh  on  Hallopus  and  Other 
Dinosaurs.  /6id.,  June,  1890,  Vol.  24, 
pp.  569-571. 

An  Apparently  New  Species  of  Chelys. 
Ibid.,  Oct.  1890,  Vol.  24,  pp.  967-968. 

On  the  Characters  and  Systematic  Posi- 
tion of  the  Large  Sea  Lizards,  Mosa- 
sauridse.  Science,  Nov.  7,  1890,  Vol. 
16,  No.  405,  p.  262. 

Two  New  Species  of  Tortoises  from  the 
South.  Ibid.,  Nov.  7,  1890,  Vol.  16, 
No.  405,  pp.  262-263. 

The  Problems  of  Comparative  Osteology. 
Ibid.,  1890,  Vol.  16,  No.  407,  pp.  281- 
282. 

Das  Variieren  der  Eidechsen-Gattung 
Tropiduriis  auf  den  Galapagos  Inseln 
und  Bemerkungen  iiber  den  Ursprung 
der  Inselgruppe.  Biol.  Centralbl., 
1890,  Bd.  10,  Nos.  15  und  16,  pp.  475- 
483. 

The  Very  Peculiar  Tortoise,  Carettochelys 


Ramsay,  from  New  Guinea.     Science, 

Apr.  3,  1891,  Vol.  17,  No.  426,  p.  190. 
American  Box  Tortoises.     Ibid.,  Apr.  3, 

1891,  Vol.  17,  No.  426,  pp.  190-191. 
The   Horned    Saurians    of    the    Laramie 

Formation.     Ibid.,  Apr.  17,  1891,  Vol. 

17,  No.  428,  pp.  216-217. 
The  Lower  Jaw  of  Sphenodon.  American 

Naturalist,   May,   1891,   Vol.  25,  pp. 

489-490. 
Notes  on  the  Trionychian  Genus  Peloche- 

lys.    Ann.  Mag.  Nat.  Hist.,  May,  1891, 

(6)  Vol.  7,  pp.  445-446. 
Remarks  on  the  Reptiles  generally  called 

Dinosauria.       American     Naturalist, 

May,  1891,  Vol.  25,  pp.  434-454. 
On  the  Origin  of  the  Galapagos  Islands. 

Ibid.,  March  and  April,  1891,  Vol.  25, 

pp.  217-229,  307-326. 
On  the  Relations  of  Carettochelys,  Ram- 
say.    Ibid.,  July,  1891,  Vol.  25,  pp. 

631-639,  Pis.  x.-xvi. 
On  Intercalation  of  Vertebrae.    Jour,  of 

Morph.,  Jan.,  1891,  Vol.4,  pp. 331-336. 
The  Pelvis  of  the  Testudinata,  with  Notes 

on    the    Evolution    of    the  Pelvis  in 

General.    Ibid. ,  1891,  Vol.  4,  No,  3,  pp. 

345-359,  13  figs. 
Notes  on  Some   Little-known  American 

Fossil  Tortoises.      Proc.    Acad.  Nat. 

Sci.  Phil.,  1891,  pp.  411-430. 
[Dr.     Baur's    Trip     to     the     Galapagos 

Islands.]     American  Naturalist,  Oct., 

1891,  Vol.  25,  pp.  902-907. 

The  Galapagos  Islands.  Proc.  Am.  Ant. 
Sac,  Oct.  21,  1891,  pp.  3-8. 

Das  Variieren  der  Eidechsen-Gattung 
Tropidurus  auf  den  Galapagos-Inseln. 
Festschr.  z.  70.  Geburtstage  B.  Leuck- 
arts.  Leipzig,  1892,  Wilhelm  Engel- 
mann,  pp.  259-277. 

Professor  Alexander  Agassiz  on  the  Origin 
of  the  Fauna  and  Flora  of  the  Gala- 
pagos Islands.      Science,    March    25, 

1892,  Vol.  19,  No.  477,  p.  176. 

Der    Carpus    der     Schildkroten.      Anat. 

Am.,   1892,  Jahrg.   7,  Nos.  7  und  8, 

pp.  206-211,  4  figs. 
On  the  Taxonomy  of  the  Genus  Emys, 

C.   Dum^ril.     Proc.    Am.    Phil.   Soc, 

1892,  Vol.  30,  pp.  40-44. 


Published  Papers. 


465 


Addition  to  the  Note  on  the  Taxonomy 

of  the  Genus  Emys,  C.  Dum^ril.   Ibid., 

1892,  Vol.  30,  p.  245. 
On  Some  Peculiarities  in  the  Structure  of 

the  Cervical  Vertebrte  in  the  Existing 

Monotremata.     American  Naturalist, 

Jan.,  1892,  Vol.  26,  p.  72. 
[Visit  to  the  Galapagos  Islands.]     Proc. 

Bost.  Soc.  Nat.    Hist.,   March,    1892, 

Vol.  25,  p.  317. 
The  Cei'vical  Vertebrae  of  the  Monotre- 
mata.     Ame7-ican    Naturalist,   May, 

1892,  Vol.  26,  p.  435. 
Bemerkungen    iiber  verschiedene    Arten 

von  Schildkroten.      Zool.  Anz.,  1892, 

No.  389,  pp.  155-159. 
Ein  Besuch  der  Galapagos-Inseln.     Biol. 

Centralhl.,  1892,  Bd.  12,  pp.  221-250. 
On  the  Morphology  of  the  Skull  in  the 

Mosasauridae.    Jour,  of  Morph.,  Oct., 

1892,  Vol.  7,  pp.  1-22,  Pis.  i.  and  ii. 
Notes  on  the  Classification  and  Taxonomy 

of  the  Testudinata.    Proc.  Am.  Phil. 

Soc,  May  5,  1893,  Vol.  31,  pp.  210-225. 

Notes  on  the  Classification  of  the  Crypto- 

dira.      American    Naturalist,     July, 

1893,  Vol.  27,  pp.  672-675. 

Two  New  Species  of  North  American  Tes- 
tudinata.   Ibid.,  July,  1893,  Vol,  27, 

pp.  675-677. 
Further  Notes  on  American  Box-Tortoises, 

Ibid.,  July,  1893,  Vol.  27,  pp.  677-678. 
G.  Jager  und  die  Theorie  von  der  Conti- 

nuitat  des    Keimprotoplasmas.    Zool. 

Anz.,  1893,  No.  425,  p.  300. 
Ueber  Eippen  und  ahnliche  Gebilde  und 

deren  Nomenclatur.    Anat.  Am.,  1893, 

Jahrg.  9,  No.  4,  pp.  116-120. 
The  Discovery  of  Miocene  Amphisbsenians, 

American  Naturalist,  Nov.,  1893,  Vol. 

27,  pp.  998-999. 
The  Relationship  of  the  Lacertilian  Genus 

Anniella    Gray,    Proc.     U.    8.    Nat. 

Mus.,  Vol  17,  No.  1005,  pp.  345-351. 
Bemerkungen    iiber    die    Osteologie   der 

Schlafengegend  der  hoheren  Wirbel- 

thiere.    Anat.  Anz.,  Dec,  1894,  Bd.  10, 

No.  10,  pp.  315-330. 
Ueber  den  Proatlas  einer  Schildkrote  (Pla- 

typeltis  spinifer  Les.).      Ibid.,   Jan., 

1895,  Bd.  10,  No.  11,  pp.  349-354,  6  figs. 
2h 


Die  Palatingegend  der  Ichthyosauria. 
Ibid.,  1895,  Bd.  10,  No.  14,  pp.  456- 
459,  1  fig. 

The  Differentiation  of  Species  on  the 
Galapagos  Islands  and  the  Origin  of 
the  Group.  Biol.  Lect.  M.  B.  L. 
Woods  Holl,  1895,  pp.  67-78. 

Pithecanthropus  erectus.  Jour.  Qeol., 
Feb.  and  March,  1895,  Vol.  3,  No.  2, 
pp.  237-238. 

The  Fins  of  Ichthyosaurus.  Ibid.,  Feb. 
and  March,  1895,  Vol.  3,  No.  2,  pp. 
238-240. 

The  Experimental  Investigation  of  Evolu- 
tion.    The  Dial,  May  1,  1893,  p.  278. 

Cope  on  the  Temporal  Part  of  the  Skull, 
and  on  the  Systematic  Position  of  the 
Mosasauridae.  A  Reply.  American 
Naturalist,  Nov.,  1895,  Vol.  29,  pp. 
998-1002. 

Ueber  die  Morphologic  des  Unterkiefers 
der  Reptilien.  Anat.  Anz.,  1895,  Bd. 
11,  No.  13,  pp.  410-415,  4  figs. 

Das  Gebiss  von  Sphenodon  (Hatteria) 
und  einige  Bemerkungen  iiber  Prof. 
Rud.  Burckhardt's  Arbeit  fiber  das 
Gebiss  der  Sauropsiden.  Anat.  Anz., 
1895,  Bd.  11,  No.  14,  pp.  436-439. 

The  Paroccipital  of  the  Squamata  and  the 
Affinities  of  the  Mosasauridae  Once 
More.  A  Rejoinder  to  Prof.  E.  D, 
Cope.  American  Naturalist,  Feb.,  1896, 
Vol.  30,  pp.  143-147,  PI.  iv. 

Nachtrag  zu  meiner  Mittheilung  liber  die 
Morphologic  des  Unterkiefers  der  Rep- 
tilien. Anat.  Anz.,  1896,  Bd.  11,  Nos. 
18  und  19,  p.  569. 

Review  of  Dr.  A.  E.  Ortmann's  "Grund- 
ztige  der  marinen  Thiergeographie. " 
Science,  March  6,  1896,  Vol.  3,  No.  62, 
pp.  359-367. 

The  Stegocephali.  A  Phylogenetic  Study. 
Anat.  Anz.,  1896,  Bd.  11,  No.  22,  pp. 
657-673,  8  figs. 

Mr.  Walter  E.  Collinge's  "Remarks  on 
the  Preopercular  Zone  and  Sensory 
Canal  of  Polypterus."  Ibid.,  1896,  Bd. 
11,  Nos.  9  und  10,  pp.  247-248. 

Professor  Cope's  Criticisms  of  my  Draw- 
ings of  the  Squamosal  Region  of  Cono- 
lophus   subcristatus  Gray  (American 


466 


Titles  of 


NaUiralist.  Feb.,  1896,  pp.  148-140), 
and  a  Few  Remarks  about  his  Draw- 
ings of  the  Same  Object  from  Stein- 
daclmer.  /6i-rf.,AprU,  18'J6,  Vol.  UO, 
pp.  327-329. 

Bemerkungen  zu  Prof.  Dr.  O.  Bottger's 
Beferat  iiber  :  Seeley,  H.  G.  on  Theco- 
doutosaurus  and  Palaeosaurus.  Zool. 
Centralbl.,  Jahrg.  3,  No.  11,  1896, 
p.  896. 

Der  Schadel  einer  neuen,  grossen  Schild- 
krote  (Adelochelys)  aus  dem  zoologis- 
chen  Museum  in  Munchen.  Anat. 
Anz.,  1896,  Bd.  12,  Nos.  12  und  13, 
pp.  314-319,  4  figs. 

Bemerkungen  iiber  die  Phylogenie  der 
Schildkroten.  Tbid.,  1896,  Bd.  12,  Nos. 
24  und  25,  pp.  561-570. 

On  the  Morphology  of  the  Skull  of  the 
Pelycosauria  and  the  Origin  of  Mam- 
mals. (With  E.  C. Case.)  76id.,  1897, 
Bd.  13,  Nos.  4  und  5,  pp.  109-120, 
3  figs. 

Remarks  on  the  Question  of  Intercalation 
of  Vertebrae.  Zoological  Bulletin, 
Aug.,    1897,    Vol.    1,   No.    1,   pp.  41- 

55. 

Birds  of  the  Galapagos  Archipelago  :  A 
Criticism  of  Mr.  Robert  Ridgway's 
Paper.  Amei-ican  Naturalist,  Sept., 
1897,  Vol.  31,  pp.  777-784. 

Archegosaurus  [Review  of  0.  Jackels's 
"Die  Organisation  von  Archegosau- 
rus "].  Ibid.,  Nov.,  1897,  Vol.  31,  pp. 
975-980. 

New  Observations  on  the  Origin  of  the 
Galapagos  Islands,  with  Remarks  on 
the  Geological  Age  of  the  Pacific 
Ocean.  Ibid.,  Aug.,  1897,  Vol.  31,  pp. 
661-680,  and  Oct.,  1897,  pp.  864-896 
(incomplete). 

HENRY  BENNER:  — 

B.S.,  State  Normal  School,  West  Chester, 
Pa.,  1885;  M.S.,  ibid,  1887,  and  Uni- 
versity of  Michigan,  1889  ;  Fellow  in 
Mathematics,  Clark  University,  1889- 
90  ;  Instructor  in  Mathematics,  Prepara- 
tory School,  Northwestern  University, 
1890-92 ;  Instructor  in  Mathematics, 
Chicago  Manual  Training  School,  1892-. 


JOHN  A.    BERGSTROM  : — 

A.B.,  Wesleyan  University,  Mlddletown, 
Conn.,  1890  ;  Fellow  in  Psychology, 
Clark  University,  1891-94;  Ph.D., 
Clark  University.  1894  :  Assistant  Pro- 
fessor of  Psychology  and  Pedagogy, 
Indiana  University,  1894-96 ;  Associate 
Professor  of  Psychology  and  Pedagogy, 
ibid,  1896-. 

Author  of :  — 

Experiments  upon  Physiological  Memory 
by  Means  of  the  Interference  of  Asso- 
ciations. Am.  Jour,  of  Psy.,  April, 
1893,  Vol.  5,  pp.  356-369. 

An  Experimental  Study  of  Some  of  the 
Conditions  of  Mental  Activity.  Ibid., 
Jan.,  1894,  Vol.  6,  pp.  247-274. 

The  Relation  of  the  Interference  to  the 
Practice  Effect  of  an  Association. 
Ibid.,  June,  1894,  Vol.  6,  pp.  433-442. 

School  Hygiene.  (Translation  of  Dr. 
Ludwig  Kotelmann's  Ueber  Schul- 
gesundlieitspflege.  With  Edward  Con- 
radi.)  Bardeen,  Syracuse,  N.  Y. ,  1899, 
391  pp. 

ADOLF   BERNHARD:  — 

A.B.,  Johns  Hopkins  University,  1889  ; 
Teacher  of  Mathematics  and  Science, 
National  German-American  Teachers' 
Seminary,  Milwaukee,  Wis.,  1889-91  ; 
Fellow  in  Chemistry,  Clark  Univer- 
sity, 1891-92  ;  Fellow  in  Chemistry, 
University  of  Chicago,  1892-94;  Ph.D., 
University  of  Chicago,  1894  ;  Laboratory 
Assistant  in  Chemistry,  ibid.,  1894-95. 

Author  of  :  — 

Ueber  die  Einfiihrung  von  Acylen  in  den 
Benzoylessigather  (Thesis).  Chicago, 
1894,  pp.  4.3. 

FRANZ   BOAS:— 

Ph.D.,  Kiel,  1881  ;  Expedition  to  Baffin 
Land,  1883-84  ;  Privatdocent,  University 
of  Berlin,  Assistant  Royal  Ethnographi- 
cal Museum  of  Berlin,  1884-86  ;  Expedi- 
tion to  British  Columbia,  1886-87  ;  As- 
sistant editor  of  Science,  1887-89;  Do- 
cent  in  Anthropology,  Clark  Univer- 
sity, 1889-92  ;  Cliief  Assistant,  Depart- 


Published  Papers. 


467 


ment  of  Anthropology,  World's  Colum- 
bian Exposition,  Chicago,  1892-94 ;  Ex- 
pedition to  Alaska,  British  Columbia,  and 
California,  1895  ;  Assistant  Curator, 
Department  of  Anthropology,  American 
Museum  of  Natural  History,  New  York, 
1896- ;  Lecturer  on  Anthropology,  Colum- 
bia University,  1896-99  ;  Professor  of  An- 
thropology, ibid.^  1899-  ;  Member  of  :  the 
New  York  Academy  of  Sciences,  the 
American  Statistical  Association,  the 
American  Psychological  Association,  the 
American  Eolk-Lore  Society,  the  Berlin 
Anthropological  Society,  the  Berlin  Geo- 
graphical Society  ;  Corresponding  mem- 
ber of  the  Anthropological  Society  of 
Vienna,  the  Imperial  Society  of  Friends 
of  Natural  Sciences,  Anthropology,  and 
Ethnology  at  Moscow,  the  Roman  An- 
thropological Society,  the  Anthropological 
Society  of  Paris,  the  Anthropological 
Society  at  Washington,  the  American 
Antiquarian  and  Numismatic  Society  of 
Philadelphia  ;  Past  Vice-President  of  the 
Anthropological  Section  of  the  American 
Association  for  the  Advancement  of 
Science  ;  Associate  Editor  of  the  Inter- 
nationales ArcMv  fur  Ethnographie,  and 
of  the  American  Anthropologist,  N.  S. 

Author  of  :  — 

Beitrage  zur  Erkenntniss  der  Farbe  des 
Wassers.  Inaugural  Dissertation.  Kiel, 
1881. 

Ein  Beweis  des  Talbotschen  Satzes.  An- 
nalen  der  Physik  und  Chemie,  1882, 
pp.  359-362. 

Ueber  eine  neue  Form  des  Gesetzes  der 
Unterschiedsschwelle.  Pfliiger^s  Ar- 
cMv, 1881,  pp.  493-500. 

Ueber  die  verschiedenen  Formen  des 
Unterschiedsschwellenwerthes.  Ibid., 
1882,  pp.  214-222. 

Ueber  die  Berechnung  der  Unterschieds- 
schwelle nach  der  Methode  der  richti- 
gen  und  falschen  Falle.  Ibid.,  1882, 
pp.  84-94. 

Die  Bestimmung  der  Unterschiedsemp- 
findlichkeit  nach  der  Methode  der 
iibermerklichen  Unterschiede.  Ibid., 
1882,  pp.  562-566. 


Ueber  die  Grundaufgabe  der  Psycho- 
physik.     Ibid.,  1882,  pp.  566-576. 

Ueber  den  UnterschiedsschweUenwerth 
als  das  Mass  der  Intensitat  psychischer 
Vorgange.  Philosophische  Monats- 
hefte,  1882,  pp.  367-375. 

Ueber  die  ehemalige  Verbreitung  der 
Eskimos  im  arktisch-amerikanischen 
Archipel.  Zeitschrift  der  Gesellschaft 
fur  Erkunde,  1883,  pp.  118-136. 

Die  Wohnsitze  der  Neitchillik  Eskimos. 
Ibid.,  1883,  pp.  161-172. 

Arctic  Exploration  and  its  Object.  Pop. 
Sci.  Mon.,  May,  1885,  Vol.  27,  pp. 
78-81. 

Bemerkungen  zur  Topographic  der  Hud- 
son Bay.  Petermann'' s  Mittheilungen, 
1885,  pp.  424-426. 

Baffin  Land.  Geographische  Ergebnisse 
einer  in  den  Jahren  1883  und  1884  un- 
ternommenen  Forschungsreise.  Gotha, 
1885,  104  pp.,  2  maps. 

Die  Sprache  der  Bella  Coola  ludianer. 
Verh.  Anthrop.  Ges.,  Berlin,  1886,  pp. 
202-206. 

Zur  Ethnologic  von  Britisch  Columbien. 
PetermaivV s  3Iittheilungen,  1887. 

Mittheilungen  iiber  die  Bilqula  Indianer. 
Originalmittheilungen  aus  dem  K. 
Museum  fur  Volkerkunde,  Berlin, 
1885,  pp.  177-182. 

On  certain  songs  and  dances  of  the  Kwa- 
kiutl  Indians.  Jour.  Am.  Folk-Lore, 
April-June,  1888,  Vol.  1,  pp.  49-64. 

Meteorologische  Beobachtungen  im  Cum- 
berland Sunde.  Annalen  der  Hydro- 
graphie,  1888,  pp.  241-262. 

The  Game  of  Cat's  Cradle.  Internatio- 
nales Arcfiiv  fur  Ethnographie,  1888. 

Chinook  Songs.  Jour.  Amer.  Folk-Lore, 
1888,  pp.  220-226. 

Das  Fadenspiel.  Mittheilungen  der  An- 
thropologischen  Gesellschaft,  Vienna, 
1888,  p.  85. 

Sagen  der  Eskimos  von  Baffin  Land. 
Verh.  der  Berliner  Anthropologischen 
Gesellschaft,  1888,  pp.  398-405. 

The  Study  of  Geogi-aphy.  Science,  1887, 
Vol.  9,  p.  157. 

Arrangement  of  Ethnological  Collections. 
Ibid.,  1887,  Vol.  9,  pp.  485,  587,  614. 


4G8 


Titles  of 


Ice  and   Icebergs.      Ihid.^   1887,  Vol.  9, 

p.  324. 
Formation  and   Dissipation  of  Seawater 

Ice.     Ibid.,  Vol.  10,  p.  118. 
The   Eskimo  Tribes.      Review  of  Kink's 

Eskimo  Tribes.    Ibid.,  Vol.  10,  p.  271. 
Eskimo  and  Indian.     Ibid..,  Vol.   10,  p. 

273. 
The   Central    Eskimo.     Sixth  An.    Bep. 

Bur.   Ethn.,    Washington,    1888,    pp. 

399-669. 
Die     Eisverhaltnisse     des     siidostlichen 

Theiles      vou      Baffin-Land.      Beter- 

mann^s  3Iittheilungen,  1888,  pp.  296- 

298,  18  plates. 
Eskimo  Tales  and  Songs  (Texts).      H. 

Rink  and  F.  Boas.     Jour.  Am.  Folk- 
Lore,  Vol.  2,  pp.  123-131. 
Notes     on    the    Snanaimuq.      American 

Anthropologist,  1889,  pp.  321-328. 
Die    Ziele  der  Ethnologic.      New  York, 

1889,  30  pp. 

Fourth  Report  of  the  Committee  on  the 
Northwestern  Tribes  of  Canada.  British 
Ass''n  Adv.  Science,  1888,  pp.  1-10. 

Fifth  Report  of  the  Committee,  1889,  pp. 
1-96. 

Sixth  Report,  1890,  pp.  1-163. 

Seventh  Report,  1891,  pp.  1-40,  4  tables. 

Ninth  Report,  1894,  pp.  1-16. 

Tenth  Report,  1895,  pp.  1-74,  11  tables. 

Eleventh  Report,  1896,  pp.  1-23. 

A  Critique  of  Psycho-Physic  Methods. 
Science,  Vol.  11,  p.  119. 

The  Indians  of  British  Columbia.  Bop. 
Sci.  Mon.,  March,  1888,  Vol.  32,  pp. 
628-636. 

Is  Stanley  Dead  ?    Nor.  Am.  Rev.,  1888. 

On  Alternating  Sounds.  American  An- 
thropologist, 1889,  pp.  47-53. 

On  the  Census  Maps  of  the  United  States. 
Science,  Vol.  12. 

Cranium  from  Yucatan.    Am.  Antiq.  Sac, 

1890,  pp.  350-357. 

The  Use  of  Masks  and  Head  Ornaments 
in  British  Columbia.  Intern'' I  Arch. 
Eth.,  1890. 

Mixed  Races.  Science,  1891,  Vol.  17,  p. 
179. 

Dissemination  of  Tales  in  America.  Jour. 
Am.  Folk-Lore,  1891,  pp.  13-30. 


Petroglyph  in  Vancouver  Island.  Verh. 
der.  Berliner  Ges.  fur  Anth.,  1891,  pp. 
158-169. 

Sagen  der  Kootenay.  Ibid.,  pp.  159- 
172. 

Notes  on  the  Chemakum  Language.  Amer- 
ican Anthropologist,  1892,  pp.  37-44. 

Vocabularies  from  the  North  Pacific 
Coast.  Trans.  Am.  Bhil.  Soc,  1891, 
pp.  30. 

Chinook  Jargon.     Science,  Vol.  19,  p.  474. 

The  Growth  of  Children.  Ibid.,  Vol. 
19,  pp.  256-258,  281-283. 

Anthropologic  in  Amerika.  Correspon- 
denzblatt  deutsch.  Anth.  Gesellschaft, 
1892,  pp.  114-116. 

Notes  on  the  Chinook  Language.  Ameri- 
can Anthropologist,  1883,  pp.  55-63. 

The  Growth  of  Children.  Science,  1892, 
Vol.  26,  p.  351. 

Vocabulary  of  the  Kwakiutl  Language. 
Am.  Bhil.  Soc,  1892,  pp.  34-82. 

Eskimo  Songs  and  Tales.  Jour.  Am. 
Folk-Lore,  1894,  pp.  45-50. 

Correlation  of  Anatomical  and  Physiolog- 
ical Measurements.  American  Anthro- 
pologist, 1894,  pp.  313-324. 

Linguistische  Resultate  einer  Reise  in 
Baffin  Land.  Mittheilungen  der  An- 
thropologischen  Gesellschaft,  Vienna, 
1894,  pp.  97-114. 

Anthropology  of  the  North  American 
Indians.  Intern^  Cong.  Anth. ,  Chicago, 
1894,  pp.  37-49. 

Classification  of  Languages  of  the  North 
Pacific  Coast.     Ibid.,  pp.  339-346. 

Omaha  Music.  Review.  Jour.  Am. 
Folk-Lore,  1894,  pp.  169-170. 

Remarks  on  the  Theory  of  Anthropome- 
try. International  Statistical  Con- 
gress, Chicago.  Quar.  Jour.  Amer. 
Stat.  Soc,  1893. 

The  Half-blood  Indian.  Bop.  Sci.  Mon., 
October,  1894. 

Human  Faculty  as  Determined  by  Race. 
A.  A.  A.  S.,  1894.    Reprint,  pp.  1-27. 

Chinook  Texts.  Bulletin,  Bureau  oj 
Ethnology,  Washington,  D.C.,  1894, 
pp.  1-278. 

Salishan  Texts.  Am.  Bhilos.  Soc,  1895, 
pp.  31-48. 


PitblisJied  Papers. 


469 


Notes  on  the  Eskimo  of  Port  Clarence, 

Alaska.    Jour.  Am.  Folk-Lore,  1894, 

pp.  205-208. 
Zur  Mythologie  der  Indianer  von  Wash- 
ington  und    Oregon.      Globus,   1893, 

Nos.  10-12. 
Dr.  W.  T.  Porter's  Investigations  on  the 

Growth  of  the  School  Children  of  St. 

Louis.      Science,  March  1,   1895,  pp. 

225-230.    Correspondenzhlatt  der  deut- 

schen  Anth.  Ges.,  1895. 
The     Grovyth     of    First-born     Children. 

Science,  April  12,  1895. 
Zur  Ethnologie  von  Britisch  Columbien. 

Vei'h.  d.  Ges.  fur  Erdkunde,  Berlin, 

May  4,  1895. 
Indianische  Sagen  von  der  Nordpaciflschen 

Kiiste.     A.  Asher,   Berlin,  1895.    vi. 

+  364  pp. 
The  Relations   Between    Length-breadth 

and  Length-height  Index  of  the  Skull. 

Verh.  Berliner  Ges.  fur  Anthropologie. 
The    Growth    of    United    States    Naval 

Cadets.     Science,  N.  S.,  Vol.  2,  pp. 

344-346. 
Anthropometry  of  the  Indians  of  Southern 

California.     Am.  Ass''n  for  the  Adv. 

Sci.,  1895,  pp.  261-269,  9  tables. 
Zur    Anthropologie    der    Indianer    Nord 

Amerikas.     Verh.  der  Berliner  Anth. 

Ges.,  1895,  pp.  366-411. 
Sprachen  Karte  von  Britisch  Columbien. 

Petermann^s  Mittheilungen,  1896,  No, 

1,  2  plates. 
The    Growth    of     Indian    Mythologies. 

Jour.  Am.  Folk-Lore,  1896,  pp.  1-12. 
Livi.     Antropometria  Militare.     Review. 

Science,  N.  S.,  Vol.  3,  pp.  929  ff. 
The  Growth  of  the  Head.     Ibid.,  N.  S., 

Vol.  4,  No.  80. 
Songs    of    the    Kwakiutl    Indians.     Int. 

Archiv  fur  Ethnographic,  IX.,  1896, 

pp.  1-9. 
The     Limitations    of    the     Comparative 

Method    of    Anthropology.      Science, 

Dec.  18,  1896,  pp.  901-908. 
Traditions  of  the  T'sets'a'  ut.     Jour.  Am. 
Folk-Lore,  Vol.  9,  pp.  257-268  ;  Vol. 
10,  pp.  35-48. 
The  Growth  of  Children.      Science,  Vol. 
6,  pp.  570-573. 


The  Decorative  Art  of  the  Indians  of  the 
North  Pacific  Coast.  Bull.  Amer.  Mus. 
Nat.  His.,  1897,  pp.  123-176. 

Eskimo  Songs.  Jour.  Am.  Folk-Lore, 
1897,  pp.  109-115. 

Northern  Elements  in  the  Mythology  of 
the  Navaho.  American  Anthropolo- 
gist, 1897,  pp.  371-376. 

Social  Organization  and  Religious  Cere- 
monials of  the  Kwakiutl  Indians. 
Report  of  the  U.  S.  National  Museum 
for  1895.  Washington,  1897,  pp.  311- 
736. 

Traditions  of  the  Tillamook.  Jour.  Am. 
Folk-Lore,  1898,  pp.  23-38,  133-150. 

Ehrenreich  ;  Die  Ureinwohner  Brasiliens. 
Science,  N.  S.,  Vol.  6,  pp.  880-883. 

Introduction  to  James  Teit.  Traditions 
of  the  Thompson  River  Indians  of 
British  Columbia,  1898,  pp.  1-18. 

The  Growth  of  the  School  Children  of 
Toronto.  Annual  Report  of  the  Com- 
missioner of  Education,  1896-97. 
Washmgton,  1898,  Vol.  2,  pp.  1541- 
1599. 

Cathlamet  Texts.  Nineteenth  Annual 
Beport  of  the  Bureau  of  Ethnology, 
200  pp. 

Nisqa  Texts.     Ibid.,  100  pp. 

Facial  Paintings  of  the  Indians  of  North- 
ern British  Columbia.  Memoirs  Am. 
Mus.  Nat.  His.,  Vol.  2,  pp.  1-24. 

Mythology  of  the  Bella  Coola  Indians, 
Ibid.,  pp.  25-127. 

A  Precise  Criterion  of  Species.  Science, 
Vol.  7,  No.  182,  pp.  860-861. 

Twelfth  Report  of  the  Committee  of  the 
British  Association  for  the  Advance- 
ment of  Science  on  the  Northwestern 
Tribes  of  Canada  (with  Dr.  Living- 
ston Farrand) .  Proc.  of  the  B.  A.  A.  S., 
Bristol  Meeting,  1898,  pp.  1-61,  12 
tables. 

Anthropologie  in  Nord  Amerika.  Cor- 
respbl.  der  deuts.  Ges.  f.  Anthrop., 
1898. 

Mittheilungen  aus  Amerika.  Ibid.,  1898, 
Jahrg.  29,  pp.   121-123. 

Some  Recent  Criticisms  of  Physical  An- 
thropology. American  Anthropologist, 
Jan.,  1899,  N.  S.,  Vol.  1,  pp.  98-106. 


470 


Titles  of 


The  Cephalic  Index.  Ibid.,  July,  1899, 
N.  S.,  Vol.  1,  pp.  448-461. 

EUGENE  "W.    BOHANNON:  — 

Graduate,  Indiana  State  Normal  School, 
1887;  Superintendent  of  Schools,  Brown.s- 
burg,  Ind.,  1887-88;  A.B.,  Indiana  Uni- 
versity, 1890  ;  Superintendent  of  Schools, 
Plainfield,  Ind.,  1889-91  ;  Principal,  High 
School,  Pekin,  111.,  1891-92;  A.M.,  In- 
diana University,  1892  ;  Superintendent 
of  Schools,  Rensselaer,  Ind.,  1892-95; 
Scholar  in  Pedagogy,  Clark  Univer- 
sity. 1895-96  ;  Fellow  in  Psychology, 
1896-98 ;  Professor  of  Psychology, 
Pedagogy,  and  Practice,  State  Normal 
School,  Mankato,  Minn.,  1898-. 

Author  of :  — 

Peculiar  and  Exceptional  Children.  Ped- 
agogical Seminary^  Oct.,  1896,  Vol.  4, 
pp.  3-60. 

The  Only  Child  in  a  Family.  Ibid., 
April,  1898,  Vol.  5,  pp.  475-496. 

The  Undue  Emphasis  of  Method.  Ind. 
School  Jour.,  Jan.,  1899,  pp.  1-7. 

FREDERICK   E.    BOLTON:  — 

Graduate,  State  Normal  School,  Milwau- 
kee, Wis.,  1890;  Principal,  High  School, 
Fairchild,  Wis.,  1890-91  ;  B.S.,  Univer- 
sity of  Wisconsin,  1893 ;  Principal  of 
Schools,  Kaukauna,  Wis.,  1893-95  ;  M.S., 
University  of  Wisconsin,  1896  ;  Univer- 
sity of  Leipzig,  Germany,  1896-97  ;  Hon- 
orary Fello-w  in  Psychology,  Clark 
University,  1897-98;  Ph.D.,  Clark 
University,  1898  ;  Professor  of  Psy- 
chology and  Pedagogy,  State  Normal 
School,  Milwaukee,  Wis.,  1898- ;  Mem- 
ber, Wisconsin  Educational  Club ;  Past 
Vice  President,  Wisconsin  Child  Study 
Society  ;  Member,  Wisconsin  State  Teach- 
ers' Association. 

Author  of :  — 

The  Accuracy  of  Recollection  and  Obser- 
vation. Psychological  Review,  May, 
1896,  Vol.  3,  pp.  286-295. 

The  Development  of  School  Curricula  in 
the  United  States.      Thesis  deposited 


in  Library  of  University  of  Wisconsin, 

1896,  pp.  206. 
Apperception  in  the  Study  of  Geography. 

Wis.  Jour.  Ed.,  Aug.,  1896. 
The  Importance  of  Higher  Education  to 

the  Teacher.     Ibid.,  Sept.,  1890. 
The  Training  of  Elementary  Teachers  in 

Germany.     Ibid.,  April,  1896. 
Elementary  Schools  in  Germany.     Ibid., 

June,  1897. 
A  Contribution  to  the  Study  of  Illusions. 

Am.  Jour,  of  Psy.,  Jan.,  1898,  Vol.  9, 

pp.  167-182. 
Hydro-Psychoses     (Doctorate     Disserta- 
tion).   Ibid.,  Jan.,  1899,  Vol.  10,  pp. 

171-227. 
Scientific  and  Practical  Child-study  :  The 

Province  and  the  Limitations  of  Each. 

Wis.  Jour.  Ed.,  May,  1899,  and  Child 

Study   Monthly,   May,    1899,   Vol.  5, 

pp.  7-24. 
The  Secondary   School  System   of    Ger- 
many.    The  Internat.  Ed.  Series.    D. 

Appleton  &  Co.     (In  press.) 

THADDEUS   L.    BOLTON:  — 

A.B.,  University  of  Michigan,  1889; 
Principal,  Public  Schools,  Vulcan,  Mich., 
1889-90;  Scholar  in  Psychology,  Clark 
University,  1890-91 ;  Fellow  and  As- 
sistant, 1891-92  ;  Fellow  and  Demon- 
strator, 1892-93  ;  Assistant  in  Ethnol- 
ogy, World's  Columbian  Exposition,  1893  ; 
Teacher  in  Psychology,  State  Normal 
School,  Worcester,  Mass.,  1893-1896; 
Ph.D.,  Clark  University,  1895;  Pro- 
fessor of  Psychology  and  Pedagogy,  State 
Normal  School,  San  Jos^,  Cal.,  1896-97; 
Professor  of  Philosophy  and  Education, 
University  of  Washington,  Seattle,  Wash., 
1897-98  ;  University  of  Heidelberg,  1898- 
99. 

Author  of :  — 

Brain  Model  on  a  Large  Scale,  by  Dr. 
Azoux.  Translation.  (With  H.  H. 
Donaldson.)  Am.  Jour,  of  Psy., 
April,  1891,  Vol.  4,  pp.  132-141. 

The  Size  of  the  Several  Cranial  Nerves  in 
Man,  as  indicated  by  the  Areas  of 
their    Cross-sections.     (With    H.    H. 


Published  Papers. 


471 


Donaldson.  {lUd.,  Dec,  1891,  Vol. 
4,  pp.  224-229. 

The  Growth  of  Memory  in  School  Chil- 
dren. Ihid.^  April,  1892,  Vol.  4,  pp. 
362-380. 

A  Study  of  the  Spinal  Cord  of  a  Spring- 
halt Horse.  Jour,  of  Nervous  and 
Mental  Diseases,  Jan.,  1893,  N.  S., 
Vol.  18,  pp.  7-12. 

On  the  Discrimination  of  Groups  of  Rapid 
Clicks.  Am.  Jour,  of  Psy.,  April, 
1893,  Vol.  5,  pp.  294-310. 

Rhythm.  Ibid.,  Jan.,  1894,  Vol.  6,  pp. 
145-283. 

Asymmetry  of  Body.  Eeport  of  Cal, 
State  Teachers'^  Ass'n,  June,  1897. 

Modern  Psychology  in  its  Kelation  to 
Training  of  Teachers.  Ibid.,  June, 
1897. 

What  is  the  New  Psychology  and  what 
are  its  Claims  ?  Teacher  and  Student, 
San  Jos^,  Cal,  June,  1897,  Vol.  4, 
pp.  121-126. 

Knowledge  from  the  Standpoint  of  Asso- 
ciation. (With  E.  M.  Haskell.)  Ed. 
Bev.,  May,  1898,  Vol.  15,  pp.  474- 
499. 

Die  Zuverlassigkeit  einiger  Methoden  fiir 
die  Messung  des  Ermiidungsrgades  in 
Schulkindern.  Psychol.  Arbeiten, 
herausg.  v.  E.  Kraepelin.     (In  press.) 

OSKAR   BOLZA. 

Ph.D.,  University  of  Gottingen,  1886; 
Reader  in  Mathematics,  Johns  Hopkins 
University,  1888-89  ;  Associate  in 
Mathematics,  Clark  University,  1889- 
92  ;  Associate  Professor  of  Mathematics, 
University  of  Chicago,  Jan.,  1893-Jan., 
1894 ;  Professor  of  Mathematics,  ibid., 
Jan.,  1894-. 

Author  of :  — 

Ueber  die  Reduction  Hyperelliptischer 
Integrate  auf  Elliptische.  Sitzungs- 
berichte  der  Freiburger  Naturforscheu- 
den  GeselLschaft,  1885.  Dissertation, 
Gottingen,  1886.  Math.  Annalen, 
1887,  Vol.  28,  pp.  447-456. 

Darstellung  der  Invarianten  der  Binar- 
form    sechster    Ordnung    durch    die 


Nullwerte  der  zugehorigen  Theta- 
Functionen.  Ibid.,  1887,  Vol.  30,  pp. 
478-495. 

On  Binary  Sextics  with  Linear  Transfor- 
mations into  Themselves.  Am.  Jour, 
of  Math.,  1888,  Vol.  10,  pp.  47-70. 

On  the  Consti'uction  of  Intransitive 
Groups.  Ibid.,  1889,  Vol.  2,  pp.  185- 
214. 

On  the  Theory  of  Substitution-Groups 
and  its  Applications  to  Algebraic  Equa- 
tions.    Ibid.,  1891,  Vol.  13,  pp.  1-86. 

Ueber  Kronecker's  Definition  der  Gruppe 
einer  Gleichung.  Math.  Annalen, 
1893,  Vol.  42,  pp.  253-256. 

Ueber  die  linearen  Relationen  zwischen 
den  zu  verschiedenen  singularen  Punc- 
ten  gehorigen  Fundamentalsystemen 
von  Integi'alen  der  Riemannschen  Dif- 
ferentialgleichung.  Ibid.,  1893,  Vol. 
42,  pp.  526-536. 

Netto's  Theory  of  Substitutions,  trans- 
lated by  Dr.  Cole.  Bull,  of  the  N.  Y. 
Math.  Soc,  1893,  Vol.  2,  pp.  83-106. 

On  the  Transformation  of  Linear  Differ- 
ential Equations  of  the  Second  Order 
with  Linear  Coefficients.  Am.  Jour, 
of  Math.,  1893,  Vol.  15,  pp.  264-273. 

On  Weierstrass'  Systems  of  Hyperelliptic 
Integrals  of  the  First  and  Second  Kind. 
Chicago  Math.  Congress  Papers,  1893, 
pp.  1-12. 

On  the  First  and  Second  Logarithmic 
Derivatives  of  Hyperelliptic  Sigma 
Functions.  Am.  Jour,  of  3Iath.,  1895, 
Vol.  17,  pp.  11-36. 

Die  cubische  Involution  und  die  Dreithei- 
lung  und  Transformation  dritter  Ord- 
nung der  EUiptischen  Fimctionen. 
Math.  Annalen,  1897,  Vol.  50,  pp. 
68-102. 

Zur  Reduction  hyperelliptischen  Integrale 
auf  elliptische  mittels  einer  Transfor- 
mation dritten  Grades.  Ibid.,  1898, 
Vol.  50,  pp.  314-324. 

The  Partial  Differential  Equations  for  the 
Hyperelliptic  6  —  and  5  —  Functions. 
Am.  Jour,  of  Math.,  April,  1899,  Vol. 
21,  pp. 107-125. 

Proof  of  Brioschi's  Recursion  Formula  for 
the  Expansion  of  the  Even  5  —  Func- 


472 


Titles  of 


tions  of  Two  Variables.  Am.  Jour,  of 
Math.,  April,  1899,  Vol.  21,  pp.  175- 
190. 

JAMES   W.    BOYCE:  — 

B.S  ,  University  of  Vermont,  1896;  Fel- 
low in  Mathematics,  Clark  Univer- 
sity, 1896-99. 

"WILLIAM   P.    BOYNTON:  — 

A.B.,  Dartmoutli  College  (with  honors  in 
Physics),  1890  ;  Professor  of  Physics  and 
Chemistry,  University  of  Southern  Cali- 
fornia, 1890-93 ;  A.M.,  Dartmouth  College, 
1893 ;  Graduate  Scholar  and  Assistant 
in  Physics,  ihid.,  1893-94;  Scholar  in 
Physics,  Clark  University,  1894-95  ; 
Fellow,  1895-97  ;  Ph.D.,  Clark  Uni- 
versity, 1897 ;  Instructor  in  Physics, 
University  of  California,  1897-. 

Author  of  :  — 

A  Quantitative  Study  of  the  High-Fre- 
quence Induction-Coil.  Physical  Be- 
view,  July,  1898,  Vol.  7,  pp.  35-63  ; 
Philosophical  Magazine.,  Sept.,  1898, 
5th  ser..  Vol.  46,  pp.  312-338. 

JOHN    L.    BRIDGE:  — 

B.S.,  Wesley  an  University,  Middletown, 
Conn.,  1888  ;  Assistant  in  Chemistry, 
ibid.,  1889-91  ;  Fellow  in  Chemistry, 
Clark  University,  1891-92  ;  Fellow  in 
Chemistry,  University  of  Chicago,  1892- 
93;  Ph.D.,  Clark  University,  1894; 
Instructor  in  Sciences,  Connecticut  Liter- 
ary Institution,  1893-96 ;  Instructor  in 
Sciences,  "Waterbury  High  School,  1896-. 

Author  of  :  — 

The  Ethers  of  Nitroso-phenol.  Am.  Chem. 
Jour.,  1892,  Vol.  14,  pp.  276-284. 

Ueber  die  Aether  des  Chinonoximes.  Lie- 
big'' s  Annalen,  Vol.  277,  pp.  79-105. 

The  Ethers  of  Toluchinonoxime  and  their 
bearing  on  the  Space  Isomerism  of 
Nitrogen,  (With  Wm.  Conger  Mor- 
gan.) Am.  Chem.  Jour.,  Nov.,  1898, 
Vol.  20,  pp.  761-776. 

CHARLES    L.    BRISTOL:  — 

B.S.,  New  York  University,  1883; 
Teacher  of  Natural  Sciences,    Riverview 


Academy,  Poughkeepsie,  N.  Y.,  188.3-87; 
M.S.,  New  York  University,  1888;  Pro- 
fessor of  Zoology,  State  University, 
South  Dakota,  1888-91  ;  Fellow  in 
Morphology,  Clark  University,  1891- 
92  ;  Fellow  in  Biology,  University  of 
Chicago,  1892-93  ;  Associate  Professor  of 
Biology,  New  York  University,  1893-98 ; 
Professor  of  Biology,  Ibid.,  1898-  ;  Ph.D., 
University  of  Chicago,  1894 ;  Member  of 
American  Naturalists ;  Member  of  Mor- 
phologists'  Society  ;  Member  of  New  York 
Zoological  Society  ;  Fellow  of  New  York 
Academy  of  Sciences. 

Author  of :  — 

The  Metamerism  of  Nephelis,  a  contribu- 
tion to  the  morphology  of  the  nervous 
system,  with  a  description  of  Nephelis 
Lateralis.  Journal  of  Morphology, 
Oct.,  1898,  Vol.  15,  pp.  17-72. 

ERNEST  NICHOLSON  BROWN:  — 
B.A.,  Dalhousie  University,  Halifax, 
N.S.,  1889;  Scholar  in  Psychology, 
Clark  University,  1892  ;  Assistant  in 
Ethnology,  World's  Columbian  Exposi- 
tion, 1893  ;  Principal,  Model  School, 
Levis,  Quebec,  1894-95;  Principal,  Model 
School,  Lachine,  Quebec,  1895- ;  Con- 
vener of  Committee  on  Child  Study  of 
the  Provincial  Association  of  Protestant 
Teachers  of  Quebec,  1897-. 

Author  of :  — 

Child  Study.  Educational  Becord  of  the 
Province  of  Quebec,  March,  1898,  Vol, 
18,  pp.  51-63. 

The  Spelling  Problem.  Ibid.,  May-June, 
1899,  Vol.  19,  pp.  73-92. 

ELMER   B.    BRYAN:  — 

Graduate  of  Indiana  State  Normal  School, 
1889  ;  A.B.,  Indiana  University,  1893  ; 
Principal  of  High  School,  Kokomo,  Ind., 
1893-94  ;  Teacher  of  History,  Industrial 
Training  School,  Indianapolis,  1894-96; 
Professor  of  Pedagogy,  Butler  College, 
1896-97  ;  Assistant  Professor  of  Peda- 
gogy, Indiana  University,  1897-99;  Asso- 
ciate Professor,  1899-  ;  Graduate  Student 
in  Philosophy,  Harvard  University,  Oct., 


Published  Papers. 


473 


1898-Jan. ,  1899 ;  Scholar  in  Philosophy, 
Clark  University,  Jan.-Jime,  1899. 

Author  of:  — 

School  Hygiene.  Indiana  School  Jour- 
nal, July,  1899,  Vol.  44,  pp.  393-396. 

School  Diseases.  Ibid.,  Aug.,  1899,  Vol. 
44,  pp.  465-469. 

The  Hygiene  of  Instruction.  Ibid.,  Sept., 
1899,  Vol.  44,  pp.  533-536. 

The  Care  of  the  Senses.  Ibid.,  Oct., 
1899,  Vol.  44,  pp.  593-595. 

Child  Life.  Ibid.,  Nov.,  1899,  Vol.  44, 
pp.  647-649. 

"WILLIAM  LOWE  BRYAN  :  — 

A.B.,  Indiana  Univereity,  1884;  A.M., 
1886 ;  Student,  University  of  Berlin,  1886- 
87 ;  Instructor  in  Philosophy,  Indiana 
University,  1885 ;  Associate  Professor  in 
Philosophy,  ibid.,  1885-87  ;  Professor  in 
Philosophy,  ibid.,  1887  ;  Fellow  in  Psy- 
chology, Clark  University,  Oct.,  1891- 
Jan.,  1893  ;  Ph.D.,  Clark  University, 
1892 ;  Vice-President,  Indiana  Univer- 
sity, 1893-. 

Author  of :  — 

Pscyhology  at  Indiana  University.     Am. 

Jour,  of  Psy.,  April,  1890,  Vol.  3,  pp. 

283-284. 
On  the  Development  of  Voluntary  Motor 

Ability.    Ibid.,  Nov.,  1892,  Vol.  5,  pp. 

125-204. 
Auditory  and  Visual  Memory  in  School 

Children.     F7-oc.  Internal.  Ed.  Ass''n, 

1893. 
Suggestions  on  the  Study  of  Children  by 

Teachers.     Pamphlet,  8  pp. 
Child  Study :   Systematic  and  Unsystem- 
atic.     Proc.    Dept.    of   Supt.,    1895. 

Proc.  N.  E.  A.,  1895,  pp.  412-418. 
On  the   Methods  and  Results  of   Child 

Study.     Article  in  Johnson's  Encyclo- 

pcedia. 
Syllabus  on  Imitation  of  Teacher  by  Pupil. 

(With  U.  J.  Griffith.)     Handb.  III.  Soc. 

for   Child   Stxidy,  May,  1895,  Vol  1, 

pp.  44-45. 
Science  and  Education.     Proc.  iV.  E.  A., 

1895,  pp.  161-165. 


Report  on  Work  in  Child  Study  in  Indi- 
ana.     Ibid.,  1895,  pp.  905-906. 

Scientific  and  Non-Scientific  Methods  of 
Child  Study.    Ibid.,  1896,  pp.  856-860. 

Studies  on  the  Physiology  and  Psychology 
of  the  Telegraphic  Language.  (With 
Noble  Harter.)  Psychological  Beview, 
Jan.,  1897,  Vol.  4,  pp.  27-53. 

Hygiene  of  Motor  Development.  Proc. 
Dept.  of  Supt.,  N.  E.  A.,  1897. 

Report  of  Special  Committee  on  the  Or- 
ganization of  a  Committee  on  School 
Hygiene.  National  Council  of  Educa- 
tion, 1897. 

Plato  the  Teacher.  Being  Selections  from 
the  Apology,  Euthydemus,  Protagoras, 
Symposium,  Phaedrus,  Republic,  and 
Phsedo  of  Plato.  Edited  with  Intro- 
duction and  Notes.  (With  Charlotte 
Lowe  Bryan.)  Charles  Scribner's 
Sons,  New  York,  1897.     xh.  +  454  pp. 

The  Republic  of  Plato.  With  Studies 
for  Teachers  (with  Charlotte  Lowe 
Bryan).  Charles  Scribner's  Sons,  New 
York,  1898.     313  pp. 

Studies  on  the  Telegraphic  Language. 
The  Acquisition  of  a  Hierarchy  of 
Habits.  (With  Noble  Harter.)  Psy- 
chological Beview,  July,  1899.  Vol. 
6,  pp.  345-375. 

WARREN  G.  BULLARD:  — 

A. B.,  Brown  University,  1892;  Instruc- 
tor in  Mathematics,  Free  Academy, 
Elmira,  N.Y.,  1892-93;  Scholar  in 
Mathematics,  Clark  University,  1893- 
96  ;  Ph.D. ,  Clark  University,  1896  ; 
Instructor  in  Mathematics,  University  of 
Vermont,  1896- ;  Member  of  the  Ameri- 
can Mathematical  Society. 

Author  of :  — 

On  the  General  Classification  of  Plane 
Quartic  Curves.  Math.  Beview,  Vol. 
I.,  pp.  193-208.    (Preprint.) 

HERMON  C.  BUMPUS  :  — 

Ph.B.,  Brown  University,  1884;  Instruc- 
tor in  Zoology,  ibid.,  1885-86;  Professor 
in  Zoology  and  Geology,  Olivet  College, 
1886-89 ;  Fellow  in  Animal  Morphol- 


474 


Titles  of 


ogy,  Clark  University,  1889-90  ;  Ph.D., 

Clark  University,  1891 ;  Assistant  Pro- 
fessor, 1890-91,  and  Associate  Professor 
of  Zoology,  Brown  University,  1891-92  ; 
Professor  of  Comparative  Anatomy,  ihid.^ 
1892- ;  Assistant  Director,  Marine  Bio- 
logical Laboratory,  Woods  HoU,  Mass., 
1893-95  ;  Director  Biological  Laboratory 
of  the  U.  S.  Fish  Commission,  1898- ; 
Secretary  of  the  American  Society  of  Natu- 
ralists, 1895-99 ;  Vice-President  American 
Society  of  Naturalists,  1899-. 

Author  of :  — 

Studies  in  Zoology.  Am.  Teacher.,  1886. 
Eeptiles  and  Batrachians  of  Rhode  Island. 

Bandom  Notes  on  Nat.  Hist.,  1885-86, 

Vols.  2,  3. 
Reptilia.     Stand.  Nat.  Hist.,  1885,  Vol.  3. 
An   Inexpensive   Self-registering  Anxan- 

ometer.     Bat.  Gaz.,  1887,  Vol.  12. 
The  Embryology  of  the  American  Lob- 
ster.    Jour,  of  Morph.,  1891,  Vol.  5, 

pp.  215-262. 
A  New  Method  of    using  Celloidin  for 

Serial  Section  Cutting.     Amer.  Nat., 

Jan.,  1892,  Vol.  26,  pp.  80-81. 
A    Laboratory    Course    in    Invertebrate 

Zoology.     Henry   Holt  &  Co.,    1893. 

157  pp. 
The    Median    Eye  of  Adult    Crustacea. 

Zool.  Anz.,  1894,  p.  447. 
Laboratory  Teaching  of  Large  Classes  in 

Zoology.       Science,    March    8,    1895, 

N.  S.,  Vol  1,  pp.  260-263. 
Instinct  and  Education  in  Birds.    Ibid., 

August  21,  1896,  N.  S.,  Vol.  4,  pp.  213- 

217. 
Report  of  the  Fourteenth  Annual  Meeting 

of  the  American  Society  of  Naturalists. 

Ibid..  Feb.  28,  1896,  N.  S.,  Vol.  3,  pp. 

297-299. 
A  Review  of  "The  American  Lobster,  a 

Study  of  its  Habits  and  Development," 

by  F.  H.  Herrick.     Ibid.,  Oct.  9,  1896, 

N.  S.,  Vol.  4,  pp.  536-537. 
A  Contribution  to  the  Study  of  Variation. 

Jour,  of  Morph.,  Feb.  1897,  Vol.  12, 

pp.  455-484. 
Records    of    the    American     Society    of 

Naturalists  for  the  Meeting  of  1896. 


A  Review  of  Lloyd  Morgan's  "  Habit  and 
Instinct."  Science,  Dec.  17,  1897, 
N.  S.,  Vol.  6,  pp.  918-920. 

Report  of  the  Fifteenth  Annual  Meeting 
of  the  American  Society  of  Naturalists. 
Ibid.,  Jan.  7,  1898,  N.  S.,  Vol.  7,  pp. 
21-23. 

The  Result  of  the  Suspension  of  Natural 
Selection  as  illustrated  by  the  Intro- 
duced English  Sparrow.  Ibid.,  March 
12,  1897,  N.  S.,  Vol.  5,  pp.  423-424. 

A  Recent  Variety  of  the  Flatfish,  and  its 
Bearing  upon  the  Question  of  Discon- 
tinuous Variation.  Ibid.jFeh.  11, 1898, 
N.  S.,  Vol.  7,  pp.  197-198. 

Certain  Results  from  a  Study  of  the  Varia- 
tion of  Littorina.  Ibid.,  Feb.  11,  1898, 
N.  S.,  Vol.  7,  p.  198. 

The  Breeding  of  Animals  at  Woods  HoU 
during  the  Month  of  March,  1898. 
Science,  April  8,  1898,  N.  S.,  Vol.  7, 
pp.  485-487. 

The  Breeding  of  Animals  at  Woods  Holl 
during  the  Month  of  May,  1898.  Ibid., 
July  15,  1898,  N.  S.,  Vol.  8,  pp.  58-61. 

The  Breeding  of  Animals  at  Woods  Holl 
during  the  Months  of  Jime,  July,  and 
August,  1898.  Ibid.  Dec.  16,  1898, 
N.  S.,  Vol.  8,  pp.  850-858. 

The  Variations  and  Mutations  of  the 
Introduced  Sparrow  (Passer  domesti- 
cus).  Biological  Lectures  of  the  Ma- 
rine Biological  Laboratory.  1896-97. 
Ginn  &  Co.,  Boston,  1898,  pp.  1-15. 

The  Variations  and  Mutations  of  the  In- 
troduced Littorina.  Zoological  Bul- 
letin, Feb.,  1898,  Vol.  1,  pp.  247-259. 

A  Possible  Case  of  Mutation.  Jour.  Bos- 
ton Soc.  Med.  Sci.,  Dec.  21,  1897, 
Vol.  2,  pp.  25-26. 

The  Work  of  the  Biological  Laboratory  of 
the  U.  S.  Fish  Commission  at  Woods 
Holl.  Scie7ice,  July  22,  1898,  N.  S., 
Vol.  8,  p.  96. 

The  Identification  of  Adult  Fish  that  have 
been  Artificially  hatched.  Proceed- 
ings American  Fisheries  Society  for 
1898.  American  Naturalist,  June, 
1898,  Vol.  32,  pp.  407-412. 

Professor  James  Ingraham  Peck.  (An 
Account  of  his  Life  and  Work.)     Sci- 


Puhlished  Papers. 


475 


ence,  Dec.  2,  1898,  N.  S.,  Vol.  8,  p. 

783. 
The  Elimination  of  the  Unfit  as  illustrated 

by   the   Introduced  Sparrow    (Passer 

domesticus') .      Biological   Lectures  of 

the  Marine  Biological  Laboratory.    (In 

press. ) 
The  Return  of  the  Tilefish.    Bulletin  U.  S. 

Fish  Commission.     (In  press.) 

FREDERIC   BURK:  — 

B.L.,  University  of  California,  1883; 
Instructor  in  Literature  and  History, 
California  Military  Academy,  1889-90 ; 
Graduate  Student  in  Literature,  Univer- 
sity of  California,  1890-91 ;  Instructor  in 
Mathematics,  Berkeley  Gymnasium,  1890- 
91 ;  Graduate  Student  in  Philosophy,  Stan- 
ford University,  1891-92,  and  A.  M.,  1892 ; 
Supervising  Principal  of  Schools,  Santa 
Rosa,  Cal.,  1892-96;  Fellow  in  Psy- 
chology, Clark  University,  1896-97 ; 
Honorary  Fellow,  1897-98;  Ph.  D., 
Clark  University,  1898;  Supt.  of 
Schools,  Santa  Barbara,  Cal.,  1898-99; 
President,  State  Normal  School,  San 
Francisco,  1899- ;  President  of  the  Cal. 
State  Teachers'  Ass'n,  1899  ;  Chairman  of 
the  Department  of  Child  Study  of  the  N. 
E.  A.,  1899. 

Author  of :  — 

Magic  Wand.  (Alumni  Address  at  Stan- 
ford University,  1894,  pamphlet). 

Report  upon  the  Pedagogical  Methods 
in  the  Schools  of  Santa  Rosa  (pam- 
phlet), 1894. 

Modern  Changes  in  Superintendency. 
Pacific  Ed.  Jour.,  March  and  April, 
1895. 

Teasing  and  Bullying.  Pedagogical 
Seminary,  April,  1897,  "Vol.  4,  pp. 
336-371. 

The  Training  of  Teachers;  "The  Old 
Vievsr  of  Childhood  and  the  NevF." 
Atlantic  Monthly,  Oct.,  1897,  Vol.  80, 
pp.  547-561. 

The  Graded  System  vs.  Individual  Pupils. 
Northwestern  Monthly,  March,  1898, 
Vol.  8,  pp.  481-484. 

Grovyth  of  Children  in  Height  and  "Weight. 


Am.  Jour,  of  Psy.,  April,  1898,  Vol. 
9,  pp.  253-326. 
Normal    Schools   and    the    Training    of 
Teachers.      Atlantic    Monthly,    June, 

1898,  Vol.  81,  pp.  769-779. 

From  Fundamental  to  Accessory  in  the 
Development  of  the  Nervous  System 
and  of  Movements.  Pedagogical  Sem- 
inary, Oct.,  1898,  Vol.  6,  pp.  5-64. 

The  Evolution  of  Music  and  the  Pedagogi- 
cal Application.  Proc.  Cal.  Teachers'' 
Ass'n,  1898. 

A  Curriculum  for  the  Kindergarten  from 
a  Child's  Standpoint.     Ibid.,  1898. 

A  Study  of  the  Kindergarten  Problem. 
(With  Caroline  Frear  Burk.)  The 
Whitaker  and  Ray  Co.,  San  Francisco, 

1899.  123  pp. 

The  Kindergarten  Child  Physically. 
Proc.  N.  E.  A.,  1899. 

Child  Study  Application  to  the  Curricula 
of  the  Primary  School  and  Kinder- 
garten.    Ibid.,  1899. 

The  Influence  of  Exercise  upon  Growth. 
Am.  Phys.  Ed.  Rev.,  Dec,  1899,  Vol. 
4,  and  Pro.  N.  E.  A.,  1899. 

WILLIAM  H.  BURNHAM:  — 

A.B.,  Harvard  University  (with  Honors 
in  Philosophy),  1882  ;  Instructor  in  Witeu- 
berg  College,  1882-83  ;  Instructor  in  State 
Normal  School,  Potsdam,  N.  Y.,  1883-85; 
Fellow,  Johns  Hopkins  University,  1885- 
86 ;  Ph.D.,  Johns  Hopkins  University, 
1888;  Instructor  in  Psychology,  ibid., 
1888-89;  Docent  in  Pedagogy,  Clark 
University,  1890-92  ;  Instructor, 
1892- ;  Member  of  American  Psycho- 
logical Association. 

Author  of :  — 

Memory,  Historically  and  Experimentally 
Considered.  I.  The  Older  Conceptions 
of  Memory ;  II.  Modern  Conceptions 
of  Memory  ;  III.  Paramnesia ;  IV.  Re- 
cent Theories.  Am.  Jour,  of  Psy.,  Nov., 
1888,  Feb.,  May,  Aug.,  1889,  Vol.  2, 
pp.  39-90  ;  225-270  ;  431-464  ;  568-622. 

The  Stage  and  the  Pulpit.  Christian 
Union,  April  19,  1888,  Vol.  37,  pp. 
486-487. 


476 


Titles  of 


Training  the  Memory.  Nation,  Dec.  13, 
1888,  Vol.  47,  pp.  480-481. 

Economy  in  Intellectual  Work.  Scribner''s 
Magazine,  March,  1889,  "Vol.  5,  pp. 
306-314. 

Examination  and  Education.  Nineteenth 
Century,  Am.  Suppl.,  March,  1889, 
Vol.  25,  pp.  32-35, 

Recent  Educational  Literature.  Nation, 
Aug.  15,  1889,  Vol.  49,  pp.  132-133. 

The  New  German  School.  Pedagogical 
Seminary,  Jan.,  1891,  Vol.  1,  pp.  1.3-18. 

The  Study  of  Adolescence.  Ibid.,  June, 
1891,  Vol.  1,  pp.  174-195. 

Observation  of  Children  at  the  Worcester 
Normal  School.  Ibid.,  June,  1891, 
Vol.  1,  pp.  219-223. 

Higher  Pedagogical  Seminaries  in  Ger- 
many. Ibid.,  Dec.  1891,  Vol.  1,  pp. 
390-408. 

Illusions  of  Memory.  Scribher^s  Maga- 
zine, Feb.,  1892,  Vol.  11,  pp.  185-195. 

Outlines  of  School  Hygiene.  Pedagogical 
Seminary,  .June,  1892,  Vol.  2,  pp.  9-71. 

La  nuova  scuola  tedesca.  (Translation 
of  "The  New  German  School"  by 
Paolo  Vecchia).  Saggi  Pedagogici, 
Turin,  1893,  pp.  123-129. 

A  Scheme  of  Classification  for  Child-study. 
Pedagogical  Seminai-y,  March,  1893, 
Vol.  2,  pp.  191-198. 

Individual  Differences  in  the  Imagination 
of  Children.     Ibid.,  pp.  204-225. 

Some  Recent  German  Literature  on  Physi- 
cal Education.      Ibid.,  pp.  282-298. 

Child-study  as  the  Basis  of  Pedagogy. 
Proc.  Int.  Cong,  of  Ed.,  Chicago, 
1893,  pp.  718-720. 

Motor  Ability  in  Children  :  Development 
and  Training.  Proc.  Am.  Inst,  of 
Instruction,  Boston,  1894,  pp.  127-140. 

Un  esquema  de  classificaci6n  para  el 
estudio  del  nine.  (Translation  of 
"A  Scheme  of  Classification  for  Child- 
study).  Boletin  de  la  Institucion  libre 
de  Ensenanza,  Madrid,  April  30,  1894, 
Vol.  18,  pp.  107-112. 

Bibliographical  Notes  to  Lectures  in  School 
Hygiene.  Worcester,  Mass.,  1897. 
11  pp. 

Impurities   in  the  Air  of   Schoolrooms. 


Northwestern  Monthly,  July,  1897, 
Vol.  8,  pp.  75-80. 

Suggestions  from  the  Psychology  of  Ado- 
lescence. School  Beview,  Dec.  1897, 
Vol.  5,  pp.  14-27. 

Some  Aspects  of  the  Teaching  Profession. 
The  Forum,  June,  1898,  Vol.  25,  pp. 
481-495. 

Bibliography  of  School  Hygiene.  Proc. 
N.  E.  A.,  1898,  pp.  505-523. 

El  estudio  del  nifio  como  base  de  la  peda- 
gogia.  (Translation  of  "Child-study 
as  the  Basis  of  Pedagogy"  by  Manuel 
Valdes  Rodriguez).  Ensayos  sobre 
Edncacion  Tedrica  Practica  y  Experi- 
mental, Tomo  Secunda,  Habana,  1898, 
pp.  159-162. 

Mental  Hygiene.  Johnson's  Universal 
Cyclopaedia,  New  Edition,  1C99,  Vol. 
10. 

School  Diseases.     Ibid. 

School  Hygiene.     Ibid. 

The  Child  in  Education.  Nation,  Jan.  26, 
1899,  Vol.  68,  pp.  72-73. 

B.   C.  BURT:  — 

A.B.,  University  of  Michigan,  1875  ;  Pro- 
fessor, Indiana  State  Normal  School,  1875- 
78  ;  A.M.,  University  of  Michigan,  1879  ; 
Eellow  in  Philosophy,  Johns  Hopkins 
University,  1881  ;  Assistant  Professor, 
University  of  Michigan,  1881-87  ;  Fellow 
by  Courtesy,  Johns  Hopkins  University, 
1887 ;  Docent  in  Philosophy,  Clark 
University,  1889-90  ;  Ph.D.,  University 
of  Michigan,  1894  ;  Professsor  {ad  in- 
terim) of  Philosophy  and  Pedagogy, 
University  of  Colorado,  1894-95  ;  Agent, 
"Northwestern  Line"  and  "Santa  F6 
Route,"  Superior,  Nebraska,  1896-. 

Author  of :  — 

Shakespeare  in  the  Opinion  of  the  17th 
Century.     New  Englander,  1881. 

Watson's  Kant  and  his  English  Critics. 
Unitarian  Beview,  1882. 

Series  of  Articles  on  Greek  Philosophy. 
Unity,  Chicago,  1885-86. 

Some  Relations  between  Philosophy  and 
Literature.  Pub.  of  Phil.  Soc,  Uni- 
versity of  Michigan,  1886. 


Published  Papers. 


m 


References  for  Students  in  English  Litera- 
ture.    Pamphlet,  1887. 
Philosophical  Works  of  Professor  George 

S.  Morris.     Chronicle,  1889. 
A  Brief    History  of    Greek  Philosophy. 

Ginn  &  Co.,  Boston,  1889.     xiv.  +  296 

pp. 
Translation    of    Erdmann's    History    of 

Philosophy    from     Kant    to     Hegel. 

Swan,  Sonnenschein  &  Co.,  London. 
German  Philosophy  since  Hegel.    Educa- 
tion, April  and  May,  1890. 
Natural   Science   and  the  Philosophy  of 

Nature.     Philosophical  Review,  May, 

1892,  Vol.  1,  pp.  284-291. 
History  of  Modern  Philosophy.     2  vols. 

McClurg  &  Co.,  Chicago,   1892,  368, 

321  pp. 
Translation  of    Hegel's  Rechts-Pflichten 

und  Religionslehre. 
Translation    of    Erdmann's    Logik    und 

Metaphysik.     Macmillau  &  Co.,  New 

York. 

JOHN   CREAN   CARDWELL  :  — 

M.D.,  University  of  the  City  of  New  York, 
Medical  Department,  1888 ;  Assistant  in 
the  Physiological  Laboratory,  ibid.,  1888- 
89  ;  Fellow  in  Physiology,  Clark  Uni- 
versity, 1889-91  ;  Instructor  in  Physi- 
ology, Harvard  Medical  School,  1891-93  ; 
Lecturer  on  Physiology,  Brooklyn  College 
of  Pharmacy,  1894-98  ;  Assistant  to  the 
Chair  of  Nervous  Diseases,  Long  Island 
College  Hospital,  1897- ;  Chief  of  Clinic 
for  Nervous  Diseases,  Polhemus  Clinic, 
Brooklyn,  N.  Y.,  1898-  ;  Demonstrator  of 
Physiology,  Long  Island  College  Hospital, 
1899-  ;  Associate  Director  of  Department 
of  Physiology,  Hoagland  Laboratory, 
1899-. 

ALEXANDER  F.  CHAMBERLAIN:  — 

A.B.,  University  of  Toronto  (with  Honors 
in  Modern  Languages  and  Ethnology), 
1886  ;  A.M.,  University  of  Toronto,  1889  ; 
Fellow  in  Modern  Languages,  University 
College,  Toronto,  1887-90  ;  Examiner  in 
French  and  German,  Department  of  Ed- 
ucation, Toronto,  1888-89;  Librarian 
Canadian    Institute,    Toronto,    1889-90; 


Examiner  in  German,  University  of  To- 
ronto, 1888-91  ;  Examiner  in  Modern 
Languages,  Trinity  University,  Toronto, 
1890-91  ;  Anthropological  Researches  in 
British  Columbia,  under  the  auspices  of 
the  British  Association  for  the  Advance- 
ment of  Science,  Summer  of  1891 ;  Secre- 
tary Anthropological  Section,  American 
Association  for  the  Advancement  of  Sci- 
ence, 1894 ;  Secretary  Anthropological 
Section,  British  Association  for  the  Ad- 
vancement of  Science,  1897  ;  Fellow 
in  Anthropology,  Clark  University, 
1890-92;  Ph.D.,  Clark  University, 
1892 ;  Lecturer  in  Anthropology, 
1892-. 

Author  of :  — 

The  Relationship  of  the  American  Lan- 
guages. Proc.  Canad.  Inst.  (Toronto), 
3d  ser..  Vol.  5,  1886-87,  pp.  57-76. 

Prehistoric  Ethnology.  [Brief  Abstract.] 
Ibid.,  Vol.  5,  1886-87,  p.  144. 

The  Catawba  Language.  [Abstract.] 
Ibid.,  Vol.  6,  1887-88,  p.  26. 

The  Eskimo  Race  and  Language.  Ibid., 
Vol.  6,  1887-88,  pp.  261-337. 

A  First  Contribution  to  the  Bibliography 
of  the  Archaeology  of  the  Dominion  of 
Canada  and  Newfoundland.  Ann. 
Bep.  Canad.  Inst.,  1887-88,  pp.  54- 
59. 

The  Catawba  Language.  Toronto,  1888. 
4  pp.,  8vo. 

The  Mississaguas  of  Scugog.  [Abstract.] 
Proc.  Canad.  Inst.,  3d  ser..  Vol.  7, 
1888-89,  pp.  2-3. 

Deluge  Myths  of  Canadian  Indians.  [Ab- 
stract.]    Ibid.,  pp.  11-12. 

Archaeology  of  Scugog  Island.  [Abstract.] 
Ibid.,  pp.  14-15. 

The  Language  of  the  Mississaguas  of 
Scugog.  [Abstract.]  Ibid.,  pp.  213- 
215. 

The  Origin  and  Development  of  Gram- 
matical Gender.  [Abstract.]  Ibid., 
pp.  216-217. 

A  Second  Contribution  to  the  Bibliography 
of  the  Archaeology  of  Canada.  Ann. 
Bep.  Canad.  Inst.,  1888-89,  pp.  102- 
118. 


478 


Titles  of 


Notes  on  the  Negro  Words  lagniappe, 
buccra,  goober.  Science,  July  13,  1888, 
p.  23. 

Mississagua  Etymology.  Ibid.,  Sept.  14, 
p.  132. 

The  Archaeology  of  Scugog  Island.  Port 
Perry,  1889.     4  pp.,  8vo. 

Notes  on  the  History,  Customs,  and  Be- 
liefs of  the  Mississagua  Indians.  Jour. 
Am.  Folk-Lore,  Vol.  1,  1888,  pp.  150- 
160. 

Tales  of  the  Mississaguas.    I.     Ibid..,  Yo\. 

2,  pp.  141-147. 

A  Mohawk  Legend  of  Adam  and  Eve. 
Ibid.,  Vol.2,  pp.  228,  311. 

Algonkin  Onomatology,  with  some  Com- 
parisons with  Basque.  [Abstract.] 
Proc.  Am.  Ass''n  Adv.  Sci.,  Vol.  38, 
1889,  pp.  351-352. 

The  Two  Brothers  :  A  Mississagua  Leg- 
end.    [Abstract.]    Ibid.,  pp.  352-353. 

Words  of  Indian  Origin  in  the  French 
Canadian  Dialect  and  Literature.  Am. 
Notes  and  Queries  (Philadelphia),  Vol. 
1,  1888,  pp.  220-221,  232-233,  258-259, 
270-271,  278-279,  293-294,  305-306; 
Vol.  2,  1888-89,  pp.  2-3,  16-17,  30-31, 
52-53,  62-63,  76-77,  87-88,  99-100, 
124-125  ;  Vol.  4,  1889,  pp.  77-78. 

Who  was  "Etowokoam,"  mentioned  in 
Spectator,  No.  50  ?  Ibid.,  Voh  2,  pp. 
287-288. 

The  Etymology  of  Terrapin.     Ibid. ,  Vol. 

3,  pp.  210-211. 

The  Etymology  of  Tucquan.     Ibid.,  Vol. 

3,  pp.  262-263  ;  Vol.  4,  p.  324. 
The  Derivation  of  Chicago.     Ibid.,  Vol.  4, 

pp.  36,  91-92. 
The  Names  of  the  Humming  Bird.     Ibid. , 

Vol.  4,  pp.  206-208. 
New  York  Dialect  Forms.     Ibid. ,  Vol.  3, 

pp.  295-296. 
Slav  Proverbs.      '  Varsity  (University  of 

Toronto),  April  7,  1888. 
Etymology  of  Horse-Radish.     Am.  Notes 

and  Queries,  Vol.  2,  1889,  pp.  119-120. 
Etymologies    of    Acadia,    gore,    undern, 

goober,  Saginaw,   Key   West,  cockle. 

Gal,   elfetrich,  Manhattan,   moonack, 

hurrah,  chipmunk,  plaquemine.    Ibid., 

Vol.  1,  p.  285  ;  Vol.  2,  pp.  69,  310,  311  ; 


Vol.  3,  pp.  8, 9, 10, 103, 107  ;  Vol.  4,  pp. 
34,  164,  155,  214. 
Hiawatha  in  Flemish.     Ibid.,  Vol.  3,  pp. 

85-87. 
Etymology  of  Fad.     Ibid.,   Vol.   3,   pp. 

154-155. 
Mississagua    Place    Names.      Jour.   Am. 

Folk-Lore,  Vol.  3,  1890,  p.  74. 
Tales  of  the  Mississaguas.  II.     Ibid.,  pp. 

149-154. 
A  Negro  Creation  Legend.     Ibid.,  p.  302. 
The    Indians    of    Canada.       [Abstract.] 

Trans.  Canad.  Inst.,  Vol.  1,  1890-91, 

pp.  18-19. 
The  American  Indian  in  Literature.    [Ab- 
stract.]    Ibid.,  pp.  33-34. 
Mohawk  Folk-Lore.      Science,  Vol.    16, 

1890,  p.  289. 
The  Prehistoric  Naturalist.     Univ.  Quart. 

Bev.  (University  of  Toronto),  Vol.  1, 

1890,  pp.  179-197. 
Dialect    Research    in    Canada.      Dialect 

Notes,  Vol.  1,  1890,  pp.  43-56. 
Contributions  toward  a  Bibliography  of 

the   Archaeology  of   the  Dominion  of 

Canada  and  Newfoundland.  III.  Ami. 

Bep.  Canad.  Inst.,  1890-91,  pp.  78-82. 
The  Algonkian  Indians  of  Baptiste  Lake. 

Ibid.,  pp.  83-89. 
The  Aryan  Element  in  Indian  Dialects.  I. 

Canadian    Indian,   Vol.    1,    1890-91, 

pp.  148-153. 
The  Thunder-Bird  amongst  the  Algonkins. 

American  Anthropologist,  Vol.  3,  1890, 

pp.  51-54. 
Note  on  the  Os  Incte.     Ibid.,  Vol.  3,  p. 

104. 
Notes  on  Indian  Child  Language.     Ibid., 

Vol.  3,  pp.  237-241. 
The  Maple  amongst  the  Algonkian  Tribes. 

Ibid.,  Vol.  4,  1891,  pp.  39-43. 
Maple   Sugar  and   the    Indians.      Ibid., 

Vol.  4,  pp.  381-383. 
Folk-Etymology     in    Canadian    French. 

Modern  Language  Notes,  Vol.  6,  1891, 

202-205. 
Notes    of    French    Canadian   Folk-Lore. 

Dominion  Illustrated  (Montreal),  Vol. 

4,  1891,  pp.  12-13. 
Nanibozhu  amongst  the  Otchipw^,  Mis- 

sissagas,  and  other  Algonkian  Tribes. 


Published  Papers. 


479 


Jour.  Am.   Folk-Lore,  Vol.  4,   1891, 
pp.  193-213. 

"Words  of  Algonkian  Origin  in  the  Chinook 
Jargon.  Science,  Vol.  18,  1891,  pp. 
260-261. 

African  and  American.  The  Contact  of 
the  NegTO  and  the  Indian.  Ibid.,  Vol. 
17,  1891,  pp.  85-90. 

Classics  and  Modern  Languages  in  Europe 
and  America  since  1880,  or  Ten  Years 
of  the  New  Learning.  Toronto,  1891, 
60  pp. 

Some  Points  in  Linguistic  Psychology. 
Am.  Jour,  of  Psy.,  Vol.  6,  1892-93, 
pp.  116-119. 

Notes  on  the  Canadian  French  Dialect  of 
Granby,  P.  Q.  I.  Vocabulary.  Mod- 
em  Language  Notes,  Vol,  7,  1892,  pp. 
324-327. 

Der  Wettlauf:  Eine  Sage  der  Kftonaqa. 
Am  Ur-Quell,  UI.  Bd.,  1892,  S.  212- 
213. 

A  Mississaga  Legend  of  Nanlbozhii.  Jour. 
Am.  Folk-Lore,  Vol.  5,  1892,  pp.  291- 
292. 

The  Use  of  Diminutives  in  -ing  by  Some 
Writers  in  Low  German  Dialects. 
Pub.  Mod.  Lang.  Ass''n  Am.,  Vol.  7 
1892,  pp.  212-217. 

The  Language  of  the  Mississagas  of 
Skiigog.  A  Contribution  to  the  Lin- 
guistics of  the  Algonkian  Tribes  of 
Canada.  [Thesis.]  Philadelphia,  1892. 
84  pp.,  8vo. 

British  Association  for  the  Advancement 
of  Science.  Edinburgh  Meeting,  1892. 
Eighth  Report  on  the  Northwestern 
Tribes  of  Canada.  Report  on  the 
Kootenay  Indians  of  Southeastern 
British  Columbia.  (With  introduc- 
tion by  Horatio  Hale.)  London,  1892. 
71  pp.,  8vo. 

Human  Physiognomy  and  Physical  Char- 
acteristics in  Folk-Lore  and  Folk- 
Speech.  Jour.  Am.  Folk-Lore,  Vol. 
6,  1893,  pp.  13-24. 

The  Canadian-French  Dialect  of  Granby, 
Province  of  Quebec.  II.  Phonetics. 
Modern  Language  Notes,  Vol.  8,  1893, 
31-35. 

Einige  Wurzeln  aus  der  Sprache  der  Ki- 


tonaqa-Indianer  von  Britisch-Colum- 
bien.  Verh.  der  Berl.  Gesellsch.  f. 
Anthr.,  Ethn.  u.  Urgesch.,  1893,  S. 
419-425. 

Ueber  den  Zauber  mit  menschlichem  Blut 
und  dessen  Ceremonial-Gebrauch  bei 
den  Indianern  Amerikas.  Am  Ur- 
Quell,  IV.  Bd.,  1893,  L,  S.  1-3,  11. ,  S. 
34-37,  III.,  S.  64-65. 

Sagen  vom  Ursprung  der  Fliegen  und 
Moskiten.     Ibid.,  S.  201-202. 

Die  Natur  und  die  Naturerscheinungen  in 
der  Mythologie  und  Volkkunde  der  In- 
dianer  Amerikas.  I.  Der.  Regenbo- 
gen.    Ibid.,  S.  261-262. 

The  Physical  Education  of  Woman.  By 
Prof.  Mosso.  [Translation.]  Peda- 
gogical Seminary,  Vol.  2,  1892-93,  pp. 
226-235. 

Notes  on  the  Kootenay  Indians.  I.  The 
Name.  Am.  Antiq.  and  Orient.  Jour., 
Vol.  15,  1893,  pp.  292-294. 

Further  Notes  on  Indian  Child  Language. 
American  Anthropologist,  Vol.  6,  1893, 
pp.  321-322. 

Colour-Comparisons  in  the  Low-German 
Poets.  [Abstract.]  Trans.  Canad. 
Inst.,  Vol.  3,  1892-93,  pp.  43-44. 

"  Ch'nai-Sny."     Nation,  Vol.  56,  p.  82. 

Sulle  significazioni  laella  lingua  degli  in- 
digeni  americani  detti  Kitonaqa  (Koo- 
tenay) dei  termini  che  denotano  gli 
stati  e  le  condizioni  del  corpo  e  dell' 
animo.  Saggio  di  psicologia  filologica. 
Arch,  per  V  antrop.  e  la  etnol.  Firenze, 
Vol.  23,  1893,  pp.  393-399. 

Primitive  Woman  as  Poet.  [Abstract.] 
Proc.  Am.  Ass''n  Adv.  Sci.,  Vol.  42, 
1893,  p.  317. 

Syllabus  of  Lectures  on  the  Mythology  of 
the  North  American  Indians.  Report 
of  President  Clark  Univ.,  1893,  pp. 
123-125. 

Bibliography  to  accompany  a  Syllabus  of 
Lectures  on  the  Mythology  of  the 
North  American  Indians.  Ibid.,  pp. 
141-158. 

The  Coyote  and  the  Owl  (Tales  of  the 
•       Kootenay     Indians).      Mem.     Intern. 
Cong.    Anthrop.,  Chicago,    1894,   pp. 
282-284. 


480 


Titles  of 


A  Kootenay  Legend  :  The  Coyote  and  the 
Mountain  Spirit.  Jour.  Am.  Folk- 
Lore,  Vol.  7,  1894,  p.  195. 

Words  Expressive  of  Cries  and  Noises  in 
the  Kootenay  Language.  American 
Anthropologist,  Vol.  7,  1894,  pp.  68- 
70. 

New  Words  in  the  Kootenay  Language. 
Ibid.,  pp.  186-192. 

Life  and  Growth  of  Words  in  the  French 
Dialect  of  Canada.  I.  Modern  Lan- 
guage Xotes  (Baltimore),  Vol.  9,  1894, 
pp.  78-87. 

Life  and  Growth  of  Words  in  the  French 
Dialect  of  Canada.  II.  Ibid.,  pp. 
135-141. 

Ueber  die  Benennung  des  Pferdes  in  den 
Sprachen  anierikanischer  Indianer. 
Am  Ur- Quell,  V.  Bd.,  1894,  S.  5-6. 

Notes  on  the  Kootenay  Indians.  Second 
Paper.  Linguistic  Data.  American 
Antiq.,  Vol.  17,  1894,  pp.  271-274. 

Anthropology  in  Universities  and  Colleges. 
Pedagogical  Seminary,  Vol.  3,  Oct., 
1894,  pp.  48-60. 

Primitive  Anthropometry  and  its  Folk- 
Lore.  [Abstract.]  Proc.  Am.  Ass^n 
Adv.  Sci.,  Vol.  43,  1894,  pp.  348-349. 

Incorporation  in  the  Kootenay  Language. 
[Abstract.]     Ibid.,  pp.  346-348. 

Translation  into  Primitive  Languages  ; 
Errors  and  Pitfalls  ;  with  illustrations 
from  Algonkian  dialects.  [Abstract.] 
Ibid.,  p.  346. 

Bayou  (Etymology).  Nation,  Nov.  22, 
1894,  Vol.  59,  p.  381. 

La  Belle  Nivernaise,  par  Alphonse  Daudet, 
and  Le  Chien  du  Capitaine,  par  Louis 
!]fcnault.  Edited,  with  Lives  of  the 
Authors,  Notes,  and  Vocabulary,  by 
John  Squair,  B.A.,  and  A.  F.  Cham- 
berlain, M.A.  Toronto,  1890,  6 + 
184,  and  198  +  132  pp. 

Notes  on  the  Kootenay  Indians.  III. 
Mythology  and  Folk-Lore.  Am.  An- 
tiq. and  Orient.  Jour.,  Vol.  17,  1895, 
pp.  68-72. 

On  Words  for  "Anger"  in  Certain  Lan- 
guages. A  Study  in  Linguistic  Psy- 
chology. Am.  Jour,  of  Psy.,  Vol.  6, 
1894-95,  pp.  585-592. 


Mutation  of  Gender  in  the  French  Dialect 

of  Canada.     Modern  Language  Notes, 

Vol.  10,  pp.  232-236. 
The  Child  and  Childhood  in  Folk-Thought 

(The    Child    in    Primitive     Culture). 

Macmillan's,  N.  Y,,  1896,  x.  +  474  pp., 

8vo. 
Indian  Legends  and    Beliefs    about    the 

Squirrel   and   the   Chipmunk.      Jour. 

Am.  Folk-Lore,  Vol.  9,  1896,  pp.  48- 

50. 
The    Poetry    of    American     Aboriginal 

Speech.     Ibid.,  pp.  43-47. 
Record  of  American  Folk-Lore.      Ibid., 

pp.  204-209. 
Beitrag  zur  Pflanzenkunde  der  Naturvolker 

America's.       Verh.   d.    Berl.    Ges.   f. 

Anthr.,  1895,  S.  551-556. 
Childhood.    Address  before  Conference  of 

Lend-a-Hand    Clubs,    Lowell,    Mass., 

Feb.  1,  1896.     Ten  Times  One  Becord 
(Boston),  Vol.  3,  1896,  pp.  7-8. 
Anthropology  at  the  Toronto  Meeting  of 

the  British  Association.     Science,  N. 

S.,  Vol.  6,  1897,  pp.  575-583. 
Record  of  American  Folk-Lore.      Jour. 

Am.   Folk-Lore,  Vol.   10,    1897,    pp. 

67-75. 
In  Memoriam  :  Horatio  Hale.     Ibid.,  pp. 

60-66. 
The  Mythology  and  Folk-Lore  of  Inven- 
tion.    Ibid.,  pp.  89-100. 
Record  of  American  Folk-Lore.      Ibid., 

pp.  149-154. 
The  Unitarian  Church  as  a  Social  Institu- 
tion versus  Alcoholism.    Boston,  1897, 

15  pp. 
The  Lesson  of  the  "  Little  Child."  North- 

icestern  Monthly  (Lincoln,  Neb.),  Vol. 

7,  1898,  pp.  435-439. 
Record  of  American  Folk-Lore.     Jour. 

Am.    Folk-Lore,   Vol.    10,    1897,    pp. 

233-239. 
Darwin  and  Lincoln.      An  Anniversary 

Address.     Worcester  (Mass.)  Gazette, 

Feb.  8,  1898. 
Record  of  American  Folk-Lore.      Jour. 

Am.    Folk-Lore,    Vol.    11,    1898,    pp. 

61-66. 
The  Kootenays  and  their  Salishan  Neigh- 
bours.     Bep.   Brit.   Ass'n  Adv.   Sci. 


Published  Papers. 


481 


(Toronto,  1897),  Vol.  47,  London, 
1898,  p.  792. 

Kootenay  Indian  Drawings.  Ibid.,  pp. 
797-798. 

Record  of  American  Folk-Lore.  (Jointly 
witii  I.  C.  C.)  Jour.  Am.  Folk-Lore, 
Vol.  11,  1898,  pp.  151-158. 

Record  of  American  Folk-Lore.  (Jointly 
with  I.  C.  C.)     Ihid.,  pp.  293-297. 

On  the  Words  for  Fear  in  Certain  Lan- 
guages. A  Study  in  Linguistic  Psy- 
chology. Am.  Jour.  Fsy.,  Vol.  10, 
1898-99,  pp.  302-305. 

Ethnology  of  the  Aborigines.  In  British 
Association  for  the  Advancement  of 
Science  (Toronto  Meeting,  1897). 
Handbook  of  Canada  (Toronto,  1897), 
pp.  106-126. 

American  Indian  Names  of  "White  Men 
and  Women.  Jour.  Am.  Folk-Lore, 
Vol.  12,  1899,  pp.  24-31. 

The  Child.  A  Study  in  Human  Evolu- 
tion. (Volume  of  about  400  pages. 
In  press.) 

Art  of  the  Kootenay  Indians.  (In  prep- 
aration.) 

Mythology  of  the  Kootenays.  (In  prep- 
aration.) 

Dictionary  of  the  Kootenay  Indian  Lan- 
guage. I.  Kootenay-English.  II.  Eng- 
lish-Kootenay.     (In  preparation.) 

Three  Shapers  of  Childhood's  Genius  — 
Society,  Opportunity,  Travel.  North- 
western Monthly,  June,  1899,  Vol.  9, 
pp.  439-443. 

Record  of  American  Folk-Lore.  (With 
I.  C.  C.)  Jour.  Am.  Folk-Lore,  Vol. 
12,  1899,  pp.  136-143. 

Numerous  reviews  of  books  and  articles  in 
Journal  of  American  Folk-Lore,  He- 
view  of  Historical  Publications  relat- 
ing to  Canada,  American  Jotirnal  of 
Psychology,  Pedagogical  Seminary,  etc. 

"WILL    GRANT    CHAMBERS:  — 

Graduate,  Pennsylvania  State  Normal 
School,  Lock  Haven,  1887  ;  Instructor  in 
Mathematics,  ibid.,  1887-90;  A.B.,  La- 
fayette College  (Honors  in  English  and 
Philosophy),  1894;  Instinictor  in  Mathe- 
matics, State  Normal  School,  Indiana,  Pa., 
2i 


1894-97  ;  B.S.,  State  Normal  School,  Indi- 
ana, Pa.,  1895  ;  M.S.,  ibid.,  1897  ;  A.M., 
Lafayette  College,  1897  ;  Scholar  in 
Psychology,  Clark  University,  1897- 
98  ;  Instructor  in  Mathematics  and  Peda- 
gogy, State  Normal  School,  Indiana,  Pa., 
1899-. 

WALTER   CHANNING:  — 

Student,  Massachusetts  Institute  of  Tech- 
nology, 1867-68  ;  M.D.,  Harvard  Univer- 
sity, 1872  ;  Honorary  Scholar,  Clark 
University,  1889-90  ;  Honorary  Fel- 
low, 1890-92  ;  Professor  of  Mental 
Diseases,  Tufts  College  Medical  School, 
1895- ;  Assistant  Physician  Asylum  for  In- 
sane Criminals,  New  York,  1873-75  ;  First 
Assistant  Physician,  Insane  Hospital, 
Danvers,  Mass.  1876-78  ;  Superintendent, 
Private  Hospital  Mental  Diseases,  Brook- 
line,  Mass.,  1879- ;  Chief,  Department 
Mental  Diseases,  Boston  Dispensary  ; 
Consulting  Physician,  Boston  Aid  Soci- 
ety; Member  of  :  American  Medical  Asso- 
ciation, Massachusetts  Medical  Society, 
American  Medico-Psychological  Society, 
American  Neurological  Society,  New 
England  Psychological  Society,  Boston 
Medical  Improvement  Society,  Boston 
Medical  Library  Association,  Corporation 
Massachusetts  School  for  Feeble-minded  ; 
Honorary  Member,  Association  Institu- 
tions for  Feeble-minded  ;  Member  of : 
Council  American  Association  Advance- 
ment Physical  Education,  Boston  Society 
of  Physical  Education,  Massachusetts 
Prison  Association,  National  Conference 
of  Charities ;  Ex-president,  Brookline 
Education  Society,  and  Boston  Medico- 
Psychological  Society ;  Trustee,  New  Eng- 
land Conservatory  of  Music ;  Member, 
Brookline  School  Board. 

Author  of:  — 

Case  of  Helen  Miller.      Self-mutilation. 

Tracheotomy.  Am.  Jour,  of  Insanity. 
A  Case  of  Feigned  Insanity.    Boston  Med. 

and  Surg.  Jour.,  1878,  Vol.  98,  p.  655. 
Buildings  for  Insane  Criminals.     Proc.  of 

Conference     of    Charities,    Chicago, 

June,  1879. 


482 


Titles  of 


Care  of  the  Insane  in  Massachusetts. 
Boston  Med.  and  Surg.  Jour.  1879, 
Vol.  101,  p.  760. 

The  Study  of  Psychological  Medicine. 
Ibid.,  1880,  Vol.  102,  p.  315. 

Note  on  the  Construction  of  Hospitals  for 
Insane  Paupers.  Proc.  of  Conference 
of  Charities,  Cleveland,  June,  1880. 

Recent  Progress  in  Insane  Asylum  Man- 
agement. Boston  Med.  and  Surg. 
Jour.,  1880,  Vol.  102,  p.  243. 

The  Treatment  of  Insanity  in  its  Economic 
Aspect.  Proc.  of  Am.  Social  Sci.  Ass^n, 
Saratoga,  N.  Y.,  Sept.  8,  1880. 

The  Use  of  Mechanical  Restraint  in  Insane 
Hospitals.  Boston  Med.  and  Surg. 
Jour.,  1880,  Vol.  103,  p.  173. 

Recent  Progress  in  Insane  Asylum  Man- 
agement and  Care  of  the  Insane.  Ibid., 
1881,  Vol.  104,  p.  272. 

The    Care  of   Insane   Criminals.     Ibid., 

1881,  Vol.  104,  p.  172. 

Medical  Expert  Testimony.  Ibid.,  1881, 
Vol.  105,  p.  1. 

The  Mental  Status  of  Guiteau,  the  Assassin 
of  President  Garfield.  Ibid.,  1882, 
Vol.  106,  p.  290. 

Recent  Progress  in  Insane  Asylum  Man- 
agement   and    Construction.       Ibid., 

1882,  Vol.  106,  p.  267. 

Recent  Progress  in  the  Management  of 
Lunatic  Asylums  and  Care  of  the  In- 
sane.    Ibid.,  1882,  Vol.  107,  p.  441. 

Non-Restraint  in  Lunatic  Asylums.    Ibid., 

1882,  Vol.  107,  p.  282. 

Medical  Treatment  of  the  Insane  with 
Special  Reference  to  Opium.     Ibid., 

1883,  Vol.  108,  p.  86. 

Report  on  Recent  Progress  in  the  Con- 
struction of  Insane  Hospitals  and 
Management  of  the  Insane.  Ibid., 
1883,  Vol.  109,  p.  462. 

A  Consideration  of  the  Causes  of  Insanity. 
Fifth  Ann.  Bep.  3Iass.  Board  of 
Health,  Lunacy,  and  Charity,  1884. 

Recent  Progress  in  the  Construction  of 
Insane  Hospitals  and  Management  of 
the  Insane.  Boston  Med.  and  Surg. 
Jour.,  1884,  Vol.  110,  pp.  295  and  321. 

Report  on  the  Care  of  the  Insane.  Ibid., 
1885,  Vol.  112,  p.  342. 


Temperature  of  the  Insane,  Especially  in 
Acute  Mania  and  Melancholia.     Ibid., 

1885,  Vol.  113,  pp.  1  and  29. 

The  Connection  between  Insanity  and 
Crime.  Rep.  of  the  Com.  on  Biblio- 
graphy of  Insanity.  Pi-oc  of  Am. 
Ass^n  of  Med.  Supts.  of  Am.  InstitUr- 
tions  for  the  Insane,  Saratoga,  N.  Y., 
June,  1885. 

Recent  Progress  in  the  Care  of  the  Insane. 
Boston  Med.  and  Surg.  Jour.  1886, 
Vol.  114,  pp.  291  and  318. 

Report  of  a  Case  of  Epilepsy  of  Forty-five 
Years'  Duration,  with  Autopsy.    Ibid., 

1886,  Vol.  115,  p.  4. 

Recent  Progress  in  Care  of  the  Insane. 

Ibid.,  1887,  Vol.  116,  pp.  351-372. 
Progress  in  the  Care  of  the  Insane.     Ibid., 

1888,  Vol.  118,  p.  424. 
An  International  Classification  of  Mental 

Diseases.     Am.  Jour,  of  Insanity,  Jan., 

1888. 
Massachusetts    Lunacy    Laws.       Boston 

Med.  and  Surg.  Jour.,  1888,  Vol.  119, 

p.  97. 
Lunacy  Legislation  as  Proposed  by  Dr. 

Stephen  Smith  and  Others.    Am.  Jour. 

of  Insanity,  Jan.,  1889. 
Physical  Training  of  the  Insane.     Ibid., 

Oct.,  1889. 
Physical  Education.      Boston  Med.   and 

Surg.  Jour.,  1891,  Vol.  125,  p.  4. 
Physical  Education  of  Children.    Pi-oc.  of 

the  An7i.  Meeting  of  the  Social  Sci. 

Ass'n,  Sept.  1891. 
Evolution  of  Paranoia.     (Rep.  of  a  Case.) 

Jour,  of  Nervous  and  Mental  Diseases, 

1892,  p.  192. 
Some  Remarks  on  the  Address  Delivered 

to  the  American  Medico-Psychological 

Association  by  S.  Weir  Mitchell,  M.D., 

May  16,  1894.     Am.  Jour,  of  Insanity, 

Oct.  1894. 
Tuberculosis  in  Mental  Disease.     Boston 

Med.  and  Sxirg.  Jour.,  1894,  Vol.  131, 

p.  62. 
Physical  Training  in  Childhood.     Educa- 
tional Revieio,  Oct.,  1895,  Vol.  10,  pp. 

262-272. 
The  Importance  of  Frequent  Observations 

of  Temperature  in  the  Diagnosis  of 


Published  Papers. 


483 


Chronic  Tuberculosis.      Boston  Med. 

and  Surg.  Jour.,  Oct.  21,  1895. 
A  Case  of  Tumor  of  tlie  Thalamus,  with 

Remarks   on    the    Mental    Symptoms. 

Jour,  of  N'ervous  and  Mental  Diseases, 

Aug.,  1896. 
The  Significance  of  the  Palatal  Deformities 

of  Idiots.    Jour.  Mental  Sci.,  London, 

Jan.,  1897. 
Beginnings    of    an    Education    Society. 

Educational  Bevieio,  Nov.,  1897. 
Characteristics  of  Insanity.     Boston  3Ied. 

and  Surg.  Jour.,  Dec.  9  and  16,  1897. 
The  Relation  of  the  Medical  Profession  to 

School  Education.    Annals  of  Gynce- 

cology  and  Fcediatry,  Jan.  26,  1897. 
Physical  Training   in  the  Boston  Public 

Schools.     Am.  Physical  Ed.  Review, 

June,  1897. 
Medical  Expert  Testimony  in  the  Kelly 

Murder  Trial.     Arn.  Jour,  of  Insanity, 

No.  3,  1898,  Vol.  54. 
The  New  Massachusetts  Board  of  Insanity. 

Charities  Beview,  Oct.,  1898. 

OSCAR   CHRISMAN:  — 

Teacher  and  Principal  in  Public  Schools, 
(Owen  County,  Gosport,  Peru,  Xenia, 
Logansport),  Indiana,  1876-85  ;  Graduate, 
Indiana  State  Normal  School,  1887  ;  A.B., 
Indiana  University,  1888  ;  Principal  (Third 
Ward),  Public  School,  Houston,  Texas, 
1888-89  ;  Supt.  Public  Schools,  Gonzales, 
Texas,  1889-92  ;  Fellow  in  Pedagogy, 
Clark  University,  1892-94 ;  A.M., 
Indiana  University,  1893 ;  Student  in 
Philosophy  and  Pedagogy,  University  of 
Jena,  1894-95  ;  Ph.D.,  University  of  Jena, 
1895;  Professor  of  History  of  Education 
and  Child-study,  Kansas  State  Normal 
School,  1896-  ;  Secretary,  1898,  and  Presi- 
dent, 1899,  of  the  Kansas  Society  for 
Child-study. 

Author  of :  — 

The   Hearing  of  Children.     Pedagogical 

Seminary,  Dec,  1893,  Vol.  2,  pp.  397- 

441. 
Secret  Language  of   Children.     Science, 

1893,  Vol.  22,  p.  303  ;  1894,  Vol.  23, 

p.  18. 


The  Science  of  the  Child.  South  Dakota 
Educator,  Feb.,  1894,  p.  11. 

Vertical  Wi-iting.  Texas  School  Jour., 
1894. 

Child-study,  a  New  Department  of  Edu- 
cation. Forum,  Feb.,  1894,  Vol.  16, 
pp.  728-736. 

Contribution  to  a  Symposium  on  Child- 
study.  Interstate  School  Bevieio, 
Illinois,  June,  1894,  p.  225. 

One  Year  with  a  Little  Girl.  Educational 
Beview,  Jan.,  1895,  Vol.  9,  pp.  52-71. 

Paidologie,  Entwurf  zu  einer  Wissenschaft 
des  Kindes.  Inaugural-Dissertation 
der  philosophischen  Fakultat  der  Uni- 
verstat  Jena  zur  Erlangung  der  Doktor- 
wllrde.     Jena,  1896.     96  pp. 

Children's  Secret  Language.  Child-study 
Monthly,  Sept.,  1896,  Vol.  2,  pp.  202- 
210. 

How  a  Story  Affected  a  Child.  Ibid., 
April,  1897,  Vol.  2,  pp.  650-661. 

The  Hearing  of  School  Children.  North- 
western Monthly,  July,  1897,  Vol.  8, 
pp.  31-35. 

Motor  Control :  Its  Place  in  the  Physical 
and  Psychical  Life  of  the  Child.  State 
Normal  3fonthly,  Oct.,  1897,  Vol.  10, 
p.  3. 

Child-study  in  Texas.  Child-study 
Monthly,  Nov.,  1897,  Vol.  3,  p.  287. 
(Report  of  the  Child-study  Section  of 
the  Texas  State  Teachers'  Association 
held  at  Waco,  June  29-July  2,  1897.) 

The  Secret  Language  of  Children.  North- 
loestern  Monthly,  Vol.  8,  Oct.,  1897, 
p.  187  ;  June,  1898,  p.  649 ;  and  Jan., 
1899,  p.  375. 

Exceptionals.  State  Normal  3Ionthly, 
Jan.,  1898,  Vol.  10,  p.  51. 

Results  of  Child-study.  Education,  Feb., 
1898,  Vol.  18,  pp.  323-332. 

Religious  Ideas  of  a  Child.  Child-study 
Monthly,  March,  1898,  Vol.  3,  pp.  616- 
528. 

How  to  use  the  Library.  Western  College 
Magazine,  March,  1898,  Vol.  19,  p. 
502. 

Paidology,  the  Science  of  the  Child.  Edu- 
cational Beview,  March,  1898,  Vol.  15, 
pp.  269-284. 


484 


Titles  of 


The  Secret  Language  of  Childhood.  Cen- 
tury, May,  1898,  Vol.  56,  pp.  54-58. 

Religious  Periods  of  Child-growth.  Edxi- 
cational  lieview,  June,  1898,  Vol.  16, 
pp.  40-48. 

Child  and  Parent.  Northwestern  Monthly, 
Vol.  9,  Nov.,  1898,  p.  135  ;  Dec,  1898, 
p.  180. 

The  Pubescent  Period.  Education,  Feb., 
1899,  Vol.  19,  pp.  342-347. 

Opening  Remarks  as  President  of  the 
Kansas  Society  for  Child-study.  Child- 
study  Monthly,  Feb.,  1899,  Vol.  4,  p. 
451. 

Editorial  for  the  Child-study  Department. 
Northwestern  Monthly,  Feb.,  1899, 
Vol.  9,  p.  275. 

Child  and  Teacher.  Jour,  of  Pedagogy, 
May,  1899,  Vol.  12,  pp.  112-125. 

Courses  of  Study  for  Normal  Schools. 
Arena,  July,  1899. 

ARTHUR    L.    CLARK:  — 

S.B.,  Worcester  Polytechnic  Institute, 
1894  ;  Instructor  in  Mathematics  and 
Physics,  Bridgeton  Academy,  Me.,  1895- 
96  ;  Scholar  in  Physics,  Clark  Uni- 
versity, 1896-97  ;  Fellow,  1897-98  ; 
Instructor  in  Science,  Worcester  Academy, 
1898-. 

Author  of :  — 

A  Method  of  Determining  the  Angle  of 
Lag.  Phil.  Mag.,  April,  1896,  Vol. 
41,  pp.  369-372. 

On  the  Specific  Inductive  Capacity  of  Cer- 
tain Oils.  Physical  Beview,  Feb. ,  1898, 
Vol.  6,  pp.  120-125. 

ROBERT   CLARK:— 

A.B.,  Amherst  College,  1892;  Teaching, 
1892-97 ;  Scholar,  Clark  University, 
1897-99. 

THOMAS   H.    CLARK:  — 

B.S.,  Worcester  Polytechnic  Institute, 
1880  ;  Assistant  Superintendent  Pennsyl- 
vania Lead  Co.,  1881-84  ;  Student,  Johns 
Hopkins  University,  1884-85 ;  Assistant 
in  Chemistry,  Wesleyan  University,  1886- 
89 ;  Fellow  in  Chemistry,  Clark  Uni- 
versity,  1889-92;   Ph.D.,  Clark  Uni- 


versity, 1892  ;  Assistant  in  Chemistry, 
1892-93  ;  instructor  in  Quantitative 
Analysi.s,  Tufts  College,  1894-95;  In- 
structor in  Chemistry  and  Physics,  Clinton 
Liberal  Institute,  1895-97  ;  Instructor  in 
Chemistry  and  Physics,  State  Normal 
School,  Plymouth,  N.  H.,  1897- ;  Member 
Am.  Institute  of  Mining  Engineers,  and 
German  Chem.  Society. 

Author  of :  — 

The  Addition-Products  of  Benzo-  and  of 
Toluquinone.  Am.  Chem.  Jour. ,  Dec, 
1892,  Vol.  14,  pp.  553-576. 

Relative  Leichtigkeit  der  Kohlendioxyd- 
abspaltung  aus  den  Silbersalzen  der 
/3-Chlorcrotonsauren.  (With  Professor 
Arthur  Michael.)  Jour,  far  prakt. 
Chemie,  1895,  N.  F.,  Bd.  52,  pp.  326- 
329. 

CHARLES  -W.    CLINTON:  — 

Principal  of  Public  Schools  in  Wisconsin 
and  Minnesota ;  County  Supei'intendent, 
Wisconsin  ;  Visitor  to  the  State  Normal 
Schools,  Wiscon-sin ;  Professor,  Shattuck 
School,  Faribault,  Minn.,  1880-88;  Prin- 
cipal, St.  John's  Military  Academy,  Kan- 
sas, 1888-90;  Head  Master,  Peekskill 
Military  Academy,  1891-93 ;  Principal, 
Marmaduke  (Mo.)  Military  Academy, 
1893-94;  Ph.D.,  Ottawa  University,  1895; 
Principal,  Clinton  Classical  School,  1895- 
97 ;  Fellow^  in  Psychology,  Clark 
University,  1897-98  ;  Professor  of 
Mathematics  and  Latin,  Stamford  (Ct.) 
Preparatory  School,  1899. 

HERBERT   OTIS   CLOUQH:  — 

A.B.,  Bowdoin  College,  1896;  Scholar 
in  Mathematics,  Clark  University, 
1896-97;  Assistant  in  Mathematics, 
Bowdoin  College,  1897-98 ;  Principal 
Kennebunkport  (Me.)  High  School,  1898-. 

FREDERICK   "W.   COLEGROVE:  — 

A.B.,  Colgate  University,  1882;  A.M., 
ibid.,  1885  ;  Student,  Hamilton  Theological 
Seminary,  1882-84  ;  Principal,  Collegiate 
Institute,  Marion,  N.  Y.,  1884-89;  Pro- 
fessor of  Latin,  Colgate  University,  1889- 
92 ;  President,  Ottawa  University,  Kansas, 


Published  Papers. 


485 


1892-96;  D.D.,  University  of  Rochester, 
1893 ;  Honorary  Fellow  in  Psychology, 
Clark  University,  1896-98  ;  Ph.D., 
Clark  University,  1898  ;  Honorary 
Fellow  in  Psychology,  Oct. -Dec, 
1898  ;  Student  in  Universities  of  Europe, 
1899 ;  Professor  of  Pliilosopliy,  Univer- 
sity of  Wasliington,  Seattle,  Sept.,  1899- ; 
Member  of  the  American  Philological 
Association,  and  Kansas  Historical  So- 
ciety. 

Author  of :  — 

Freedom  of  Worship.  Our  Young  Peo- 
ple, April,  1897. 

Individual  Memories.  Am.  Jour,  of  Psy., 
Jan.,  1899,  Vol.  10,  pp.  228-256. 

The  Time  required  for  Recognition. 
Ibid.,  pp.  286-292. 

Notes  on  Mental  Standards  of  Length. 
Ibid.,  pp.  292-295. 

LEVI   L.    CONANT:  — 

A.B.,  Dartmouth  College,  1879;  Princi- 
pal of  High  Schools,  Minnesota  and 
Indiana,  1880-83 ;  Superintendent  of 
Schools,  Deadwood  and  Rapid  City,  So. 
Dak.,  1883-87 ;  A.M.,  Dartmouth  College, 
1887  ;  Professor  of  Mathematics,  Dakota 
School  of  Mines,  1887-90  ;  Scholar  in 
Mathematics,  Clark  University,  1890- 
91 ;  Assistant  Professor  of  Mathematics, 
Worcester  Polytechnic  Institute,  1891-92  ; 
A.M.  and  Ph.D.,  Syracuse  University, 
1893  ;  Associate  Professor  of  Mathematics, 
Worcester  Polytechnic  Institute,  1892-98 ; 
Professor  of  Mathematics,  ibid.,  1898-. 

Author  of :  — 

Historical  Development  of  Arithmetical 
Notation ;  and  Text  Books  in  Arith- 
metic. Pedagogical  Seminary,  June, 
1892,  Vol.  2,  pp.  149-163. 

Primitive  Number  Systems.  Smithsonian 
Report,  1892,  pp.  583-594. 

The  Teaching  of  Mathematics.  School 
Beview,  April,  1893,  Vol.  1,  pp.  210- 
217. 

Note  on  the  Translation  of  Certain  Me- 
moirs on  Infinite  Series.  Bull,  of  the 
N.Y.  Math.  Soc,  1894. 


The  Origin  of  Numeral  Words.  Proc.  A. 
A.  A.  S.,  1894. 

English  Folk  Tales  in  America.  Jour,  of 
Am.  Folk-Lore,  April-June,  1895,  Vol. 
8,  pp.  143-144. 

The  Number  Concept.  Macmillan  and 
Company,  New  York,  1896.  vi.  + 
218  pp. 

An  Application  of  the  Theory  of  Substi- 
tutions.    Am.  Math.  Soc,  Aug.,  1898. 

ALFRED    COOK:— 

A.B.,  Northwestern  University,  1877  ; 
Ph.D.,  University  of  Halle,  1886  ;  Fellow 
by  courtesy,  Johns  Hopkins  University, 
1887  ;  Superintendent  of  Schools,  Nimonk, 
111.,  1887-88;  Instructor  in  Philosophy, 
Bryn  Mawr  College,  1888-89;  Decent 
and  Lecturer  on  History  of  Philoso- 
phy, Clark  University,  1889-90  ;  Inde- 
pendent University  Extension  Lecturer 
on  Psychology  and  on  the  Philosophy  of 
History,  1896-. 

Author  of :  — 

Ueber  die  Berkeleysche  Philosophic.  C. 
A.  Kaemmerer  &  Co.,  Halle,  1886. 
48  pp. 

Harmony  of  Natural  Law  and  Free  Will, 
a  Dissertation  on  the  Kantian  Philoso- 
phy.    Bloomington,  III.,  1888.    16  pp. 

L.    P.    CRAVENS:  — 

A.B.,  Carthage  College,  1878;  A.M., 
ibid.,  1879  ;  Professor  of  Mathematics,  Mt. 
Morris  Academy,  1880-84  ;  Professor  of 
Mathematics,  Carthage  College,  1884-86  ; 
Superintendent  of  Schools,  Carthage,  111., 
1886-89 ;  Scholar  in  Mathematics, 
Clark  University,  1889-90  ;  Professor 
of  Mathematics,  State  Normal  School, 
Winona,  Minn.,  1890-91  ;  Student  in 
Mathematics,  University  of  Halle,  1891- 
92  ;  Professor  of  Mathematics,  Fort  Worth 
University,  Texas,  1892-94;  Student  in 
Mathematics,  University  of  Chicago,  1894- 
95  ;  Principal  of  Academic  Department  of 
Coe  College,  1895-96  ;  Principal  of  High 
School,  Lake  City,  Minn.,  1896-97  ;  Super- 
intendent of  Schools,  Lake  City,  Minn., 
1897-. 


486 


Titles  of 


T.    R.    CROSWELL  :  — 

A.B.,  Bowdoin  College,  1801;  rrincipal, 
Wilton  Academy,  1891-94  ;  Student  in 
Pedagogy,  Columbia  College,  1894-95 ; 
Scholar  in  Pedagogy,  Clark  Univer- 
sity, 1895-97 ;  Teacher  in  Public 
Schools  of  Chicago,  1897-98 ;  Teacher 
in  Stevens  Point  (Wis.)  Normal  School, 
1899. 

Author  of  :  — 

Courses  of  Study  in  the  Elementary 
Schools  of  the  United  States.  Peda- 
gogical Seminary,  April,  1897,  Vol.  4, 
pp.  294-335. 

A  Study  of  the  Ungraded  Schools  of 
Maine.  Maine  School  Beport,  1897, 
Appendix  II.,  pp.  1-15. 

Amusements  of  Worcester  School  Chil- 
dren. Pedagogical  Seminary,  Sept., 
1899,  Vol.  6,  pp.  314-371. 

HENRY  S.   CURTIS:  — 

A.B.,  Olivet  College,  1894;  A.B.,  Tale 
University,  1896  (Honors  in  Philosophy)  ; 
Fellow  in  Psychology,  Clark  Uni- 
versity, 1895-97;  Ph.D.,  Clark  Uni- 
versity, 1898 ;  Teacher,  N.  Y.  Public 
Schools,  1898-. 

Author  of :  — 

Learning  without  Books.  Jour,  of  Peda- 
gogy, Jan.,  1898,  Vol.  11,  pp.  86-90. 

Inhibition.  Pedagogical  Seminary,  Oct., 
1898,  Vol.  6,  pp.  65-113. 

Child-study  in  Connection  with  the  Vaca- 
tion Schools.  (With  G.  E.  Partridge.) 
Report  on  the  Vacation  Schools  and 
Playgrounds,  N.  Y.  City,  Boroughs  of 
Manhattan  and  the  Bronx,  1898,  pp. 
51-97. 

Child-study  in  Vacation  Schools.  Educa- 
tional Foundatio7is,  May,  1899. 

Child-study  in  the  Playgrounds.  Ibid., 
June,  1899. 

Plays  and  Playgrounds.     (In  press). 

ARTHUR   HILL    DANIELS:  — 

B.A.,  Olivet  College,  1887  ;  Student,  Yale 
Divinity  School,  1887-90;  B.D.,  Yale 
University,  1890  ;  Student  in  Philosophy 
and  Psychology,  Yale  University,  1890- 


92 ;  Fellow  in  Psychology,  Clark 
University,  1892-93;  Ph.D.,  Clark 
University,  1893 ;  Instructor  in  Phi- 
losophy, University  of  Illinois,  1893-95 ; 
Assistant  Professor  of  Philosophy,  ibid., 
1895-99;  Professor  of  Philosophy,  ibid., 
1899-. 

Author  of :  — 

The  New  Life  :  A  Study  of  Regeneration. 

Am.  Jour,  of  Psy.,  Oct.,  1893,  Vol.  6, 

pp.  61-106. 
The  Memory  After-image  and  Attention. 

Ibid.,  Jan.,  1895,  Vol.  6,  pp.  558-564. 

SCHUYLER   C.    DAVISSON:  — 

A.B.,  Indiana  University,  1890;  A.M., 
ibid.,  1892;  Instructor  in  Mathematics, 
ibid.,  1890-93 ;  Associate  Professor  in 
Mathematics,  ibid.,  1893-.  Fellow  in 
Mathematics,  Clark  University,  1895- 
96 ;  Student,  University  of  Tiibingen, 
Germany,  1898-99. 

GEORGE   E.    DA-WSON:  — 

A.B.,  University  of  Michigan,  1887  ;  Pro- 
fessor of  Greek  and  English  Literature, 
Carleton  Institute,  Farmington,  Mo., 
1887-88  ;  Student,  University  of  Leipzig, 
1888-89  ;  Principal,  Oil  City,  Pa.,  High 
School,  1889-91  ;  Professor  of  English  and 
Literature,  State  Agricultural  College,  So. 
Dak.,  1891-93  ;  Instructor  in  English, 
University  of  Michigan,  1893-95  ;  Fellow 
in  Psychology,  Clark  University, 
1895-97,  Ph.D.,  Clark  University, 
1897 ;  Professor  of  Psychology,  Bible 
Normal  College,  Springfield,  Mass.,  1897-. 

Author  of  :  — 

A  Stixdy  in  Youthful  Degeneracy.  Peda- 
gogical Seminary,  Dec,  1896,  Vol.  4, 
pp.  221-258. 

Series  of  Twelve  Papers  on  Child-study. 
International  Evangel,  Sept.,  1897- 
Sept.,  1898. 

The  Study  of  Man  as  Related  to  Religious 
Work.     Biblical  World,  March,  1899. 

Interest,  the  Material  of  Instruction. 
Biblical  World,  June,  1899. 

Suggestions  as  to  the  Basis  of  a  Sunday 
School  Curriculum,     Trans.  III.  Soc. 


Published  Papers. 


487 


for  Child-Study,  Apr.-July,  1899,  Vol. 
4,  pp.  10-17. 
Psychic  Rudiments  and  Morality.     Am. 
Jour,  of  Psychology.     (In  press.) 

ALFRED   T.    DE  LURY:  — 

B.A.,  University  of  Toronto  (with  Honors 
and  Medal  in  Mathematics),  1890  ;  Fellow 
in  Mathematics,  Clark  University, 
1890-91 ;  Mathematical  Master,  Whet- 
ham  College,  Vancouver,  1891 ;  Mathemat- 
ical Master,  Collegiate  Institute,  Toronto, 
1892  ;  Lecturer  in  Mathematics  and  Dean 
of  the  Residence,  University  of  Toronto, 
1892-  ;  Member  of  the  American  Mathe- 
matical Society. 

Author  of :  — 

On  Certain  Deductions  from  the  Theorem 
of  Dr.  Graves.  Papers  Math,  and 
Phys.  Soc,  Toronto  Univ.,  Year 
1890-91,  pp.  22-30. 

Clark  University.  TJie  Varsity,  Toronto, 
Jan.  27,  1891,  Vol.  10,  pp.  150-151. 

HENRY   H.    DONALDSON:  — 

A.B.,  Yale  University,  1879;  Sheffield 
Scientific  School,  1880  ;  College  of  Physi- 
cians and  Surgeons,  N.  Y.  City,  1881  ; 
Fellow,  Johns  Hopkins  University,  1881- 
83  ;  Ph.D.,  Johns  Hopkins  University, 
1885 ;  Associate  in  Psychology,  ibid., 
1887-88 ;  Assistant  Professor  of  Neu- 
rology, Clark  University,  1889-92  ; 
Professor  of  Neurology,  University  of 
Chicago,  1892-. 

Author  of :  — 

On  the  Detection  and  Determination  of 
Arsenic  in  Organic  Matter.  (Under 
Prof.  R.  H.  Chittenden.)  Am.  Chem. 
Jour.,  Oct.,  1880,  Vol.  2,  pp.  235- 
244. 

The  Influence  of  Digitaline  on  the  Work 
of  the  Heart  and  on  the  Flow  through 
the  Blood  Vessels.  (With  Dr.  L.  T. 
Stevens.)  Jour,  of  Phys.,  Jan.,  1883, 
Vol.  4,  pp.  165-197.  (See  also  note  in 
Vol.  5,  p.  45.) 

On  the  Temperature-Sense.  Mind,  July, 
1885,  Vol.  10,  pp.  399-416. 


Motor  Sensations  of  the  Skin.  (With 
Dr.  G.  Stanley  Hall.)  Ibid.,  Oct., 
1885,  Vol.   10,  pp.  557-572. 

On  the  Relation  of  Neurology  to  Psy- 
chology. Am.  Jour,  of  Psy.,  Feb., 
1888,  Vol.  1,  pp.  210-221. 

Anatomical  Observations  on  the  Brain 
and  Several  Sense-Organs  of  the  Blind 
Deaf-Mute,  Laura  Dewey  Bridgman. 
Part  I.  Ibid.,  Sept.,  1890,  Vol.  3,  pp. 
293-,342.  Part  II.  Dec,  1891,  Vol.  4, 
pp.  248-294. 

Cerebral  Localization.  Ibid.,  April,  1891, 
Vol.  4,  pp.  113-130. 

Notes  on  Models  of  the  Brain.  Ibid., 
April,  1891,  Vol.  4,  pp.  130-131. 

The  Size  of  Several  Cranial  Nerves  in 
Man  as  Indicated  by  the  Areas  of 
their  Cross-sections.  (With  T.  L. 
Bolton.)  Ibid.,  Dec,  1891,  Vol.  4, 
pp.  224-229. 

The  Extent  of  the  Visual  Area  of  the  Cor- 
tex in  Man  as  deduced  from  the  Study 
of  Laura  Bridgman's  Brain.  Ibid., 
Aug.,  1892,  Vol.  4,  pp.  503-513. 

PreUminary  Observations  on  Some 
Changes  caused  in  Nervous  Tissues 
by  Reagents,  commonly  used  to 
harden  them.  Jour,  of  Morph.,  Jan., 
1894,  Vol.  9,  pp.  123-166. 

The  Education  of  the  Nervous  System. 
Educational  Eeview,  Feb.,  1895,  Vol. 
9,  pp.  105-121. 

The  Growth  of  the  Brain.  (Contem- 
porary Science  Series.)  Walter  Scott, 
London.  Chas.  Scribner's  Sons,  New 
York,  1895.     374  pp. 

Central  Nervous  System.  Chapter  X., 
Howell's  Am.  Text-Book  of  Physiol- 
ogy, W.  B.  Saunders,  Philadelphia, 
1896,  pp.  605-743. 

Observations  on  the  Weight  and  Length 
of  the  Central  Nervous  System  and 
of  the  Legs  in  Bull-frogs  of  Different 
Sizes.  Jour,  of  Comp.  Neurol.,  Dec, 
1898,  Vol.  8,  pp.  314-335. 

D.   ELLIS   DOUTY:  — 

B.S.,    University  of    Washington,  1892; 

Assistant  in   Physics   Laboratory,  ibid., 

1895-96  ;    Tutor  in  Physics,  ibid.,  1896- 


488 


Titles  of 


98 ;  Scholar  in  PhysicB,  Clark  Uni- 
versity, 1898-99. 

L.    WAYLAND    DOV/LING  :  - 

Adrian  College,  1889-90 ;  Principal  of 
Schools,  Clayton,  Mich.,  1891-92 ;  Fel- 
low in  Mathematics,  Clark  Univer- 
sity, 1892-95;  Ph.D.,  Clark  Univer- 
sity, 1895  ;  Instructor  in  Mathematics, 
University  of  Wisconsin,  1895-98  ;  Assist- 
»  ant  Prof essor  of  Mathematics,  ibid.,  1898-; 
Member  of  the  American  Mathematical 
Society  ;  Member  of  the  Wisconsin  Acad- 
emy of  Sciences,  Arts,  and  Letters. 

Author  of :  — 

On  the  Forms  of  Plane  Quintic  Curves. 
Mathematical  Beview,  April,  1897,  Vol. 
1,  pp.  97-119. 

FLETCHER   B.   DRESSLAR:  — 

Instructor,  Vincennes  University,  1888 ; 
A.B.,  Indiana  University,  1889  ;  Princi- 
pal, High  School,  Princeton,  Ind.,  1889- 
90  ;  Superintendent  of  Schools,  Princeton, 
Ind.,  1890-91  ;  Scholar  in  Psychology, 
Clark  University,  1891-92 ;  Instruc- 
tor in  Psychology,  Indiana  University, 
Sept. -Dec,  1892;  Fellow  in  Psychol- 
ogy, Clark  University,  Jan.,  1893-July, 
1894 ;  Ph.D.,  Clark  University,  1894  ; 
Professor  of  Psychology  and  Pedagogy, 
State  Normal  School,  Los  Angeles,  Cal., 
1894-97  ;  Assistant  Professor  of  the  Sci- 
ence and  Art  of  Education,  University  of 
California,  1897-. 

Author  of  :  — 

A  Review  of  the  Genus  Simotilus.  (With 
Ernest  P.  Bicknell.)  Proc.  Acad,  of 
Nat.  Sci.,  Philadelphia,  1884. 

A  Reviev?  of  the  Family  Scombrinae 
(Illinois).  (With  Bert  Fesler.)  Bull, 
of  U.  S.  Fish  Com.,  1887. 

Temperance  Legislation  in  Indiana,  (Prize 
Essay,  University  of  Indiana.)  7n- 
diana  Strident,  March,  1887. 

Evils  of  Modern  Immigration.  (Prize 
Oration,  University  of  Indiana. )  Ibid. , 
Dec,  1889. 

Fatigue.  Pedagogical  Seminary,  June, 
1892,  Vol.  2,  pp.  102-106. 


A  Sketch  of  Old  Schoolhouses.  Ibid., 
June,  1892,  Vol.  2,  pp.  115-125. 

Some  Influences  which  affect  the  Rapid- 
ity of  Voluntary  Movement  Am. 
Jour,  of  Psy.,  Aug.,  1892,  Vol.  4,  pp. 
614-527. 

On  Facial  Vision  and  the  Pressure  Sense 
of  the  Drum  of  the  Ear.  Ibid.,  April, 
1893,  Vol.  5,  pp.  344-350. 

A  New  Illusion  for  Touch  and  an  Ex- 
planation for  the  Illusion  of  Displace- 
ment of  Certain  Cross  Lines  in  Vision. 
Ibid.,  Vol.  6,  pp.  275-276. 

A  New  and  Simple  Method  for  Comparing 
the  Perception  of  Rate  of  Movement  in 
the  Direct  and  Indirect  Fields  of  Vision. 
Ibid.,  Vol.  6,  p.  312. 

Psychology  of  Touch.  Ibid.,  June,  1894, 
Vol.  6,  pp.  50-54. 

Outline  for  a  Study  of  Habit-Degenera- 
tion. Teachers^  Handbook  for  Child- 
Study.  Published  by  Illinois  Society 
for  Child-Study,  May,  1895,  Vol.  1, 
pp.  21-23. 

Preparation  for  History  in  the  Grades. 
Normal  Exponent,  1895. 

The  New  Psychology  and  Its  Pedagogical 
Significance.  Proc.  Cal.  Teachers^ 
Ass'n,  Dec,  1895. 

Experiments  in  Psychology.  Overland 
Monthly,  Aug.,  Sept.,  Nov.,  Dec, 
1896  ;  Feb.,  March,  April,  June,  1897. 

Education  in  Hawaii.  Educational  Be- 
view,  Jan.,  1898,  Vol.  15,  pp.  50-54. 

Genetic  Psychology.  Northtcestern 
Monthly,  April,  1899,  Vol.  9,  pp. 
355-358. 

Guessing,  as  influenced  by  Number  Pref- 
erences. Pop.  Sci.  Mo.,  April,  1899, 
Vol.  54,  pp.  781-786. 

FRANK  DREW  :  — 

Superintendent  of  Schools,  Genoa,  111., 
1887-89;  A.B.,  Indiana  University, 
1890;  A.M.,  ibid.,  1891;  Scholar  in 
Psychology,  Clark  University,  1892- 
93;  Fellow,  1893-95;  Ph.D.,  Clark 
University,  1895  ;  Instructor  in  Psy- 
chology, Indiana  University,  1895-96; 
Teacher  in  State  Normal  School,  Worces- 
ter, Mass.,  1896-. 


Published  Papers. 


489 


Author  of  •-  — 

Adenoids  in  Children.  Pedagogical  Sem- 
inary, March,  1893,  Vol.  2,  pp.  307- 
309. 

Love  Poems  of  College  Students.  Ibid. 
Dec.  1893,  Vol.  2,  pp.  504-505. 

Attention :  Experimental  and  Critical. 
Am.  Jour,  of  Psy.,  July,  1896,  Vol.  7, 
pp.  533-572. 

LINDSAY   DUNCAN:  — 

B.S.,  University  of  Maine,  1897  ;  Scholar 
in    Mathematics,     Clark    University, 

1897-99 ;  Instructor  in  Mathematics  and 
Engineering,  Union  College,  Schenectady, 
N.  Y.,  1899-. 

ROBERT   K.    DUNCAN:  — 

A.B.,  University  of  Toronto,  1892  ;  Fel- 
lo'wr  in  Chemistry,  Clark  University, 
1892-93;  Instructor  in  Physics  and 
Chemistry,  Auburn,  N.  Y.,  High  School, 
1893-95  ;  Instructor  in  Physics  and  Chem- 
istry, Dr.  Julius  Sach's  Collegiate  Insti- 
tute, New  York,  1895-98;  Non-Resident 
Student,  Columbia  University,  1897-98; 
Instructor  in  Physics  and  Chemistry,  The 
Hill  School,  Pottstown,  Pa. ,  1898-. 

WILLIAM  FREDERICK  DURAND:  — 

Graduate,  U.  S.  Naval  Academy,  1880; 
Graduate,  Course  at  Sea,  1882;  Assistant 
Engineer,  U.  S.  Navy,  1882-87  ;  Graduate 
Student,  Lafayette  College,  1883-85  ; 
Ph.D.,  Lafayette  College,  1888;  Profes- 
sor of  Mechanics,  Michigan  State  Agri- 
cultural College,  1887-91  ;  Scholar  in 
Physics,  Clark  University,  Nov.  and 
Dec. ,  1889  ;  Professor  of  Marine  Engi- 
neering, Cornell  University,  1891-. 

Author  of :  — 

A  Practical  Method  of  Finding  the  Opti- 
cal Centre  of  an  Objective  and  its  Fo- 
cal Length.  Am.  Mo.  Micro.  Jour. 
Aug.,  1885,  Vol.  6,  p.  141. 

The  Fundamental  Conceptions  of  Me- 
chanics.    Privately  published,  1890. 

The  Path  of  the  Point  of  Contact  of  the 
Teeth  of  Gear  "Wheels.  Sci.  Am.  Sup- 
plement, April  26,  1890,  Vol.  29. 

An  Interesting  Experiment  with  the  Mi- 


croscope.      Am.    Mo.    Micro.    Jour., 

June,  1890,  Vol.  2,  p.  1.36. 
The  Behavior  of  Wood  under  Repeated 

and    Varying    Stress.     Trans.    Mich. 

Eng.  Soc,  1891,  p.  57. 
A  New  Form  of  Contour  Caliper.     Ibid. 

1891,  p.  62. 

Decimal  Subdivision  by  the  Eye.  Sibley 
Jour,  of  Eng.,  Jan.,  1892,  Vol.  6,  p. 
138. 

Study  of  the  Element  of  a  Screw  Propel- 
ler. Jo^ir.  of  Am.  Soc.  of  Naval  En- 
gineers, 1892,  Vol.  4,  p.  73. 

Treatment  of  Non-Algebraic  Curves  for 
Maxima  and  Minima  by  Use  of  Ordi- 
dinates.     Ibid.  p.  71. 

The  Influence  of  Shock  on  Propeller  Effi- 
ciency.    Ibid.  p.  611. 

Some  Points  in  the  Philosophy  of  the 
Steamship.     Cassier^ s  Magazine,  Nov., 

1892,  Vol.  5,  p.  35. 

Marine  Engine  Design.  Marine  Beview, 
1892,  Vol.  6,  Dec.  1,  p.  6,  and  Dec.  8, 
p.  12. 

Relative  Weight  of  Water  and  Fire  Tube 
Boilers.  American  Shipbuilder,  June 
20  and  27,  1893. 

Planning  and  Equipment  of  Modern  Ship 
and  Engine  Building  Plants.  Bep.  of 
Internal.  Eng.  Cong.,  Columbian  Ex- 
position, Div.  of  Marine  Eng.,  Vol.  2, 
No.  28. 

The  Limit  of  Propeller  Efficiency  as  De- 
pendent on  the  Surface  Form  of  the 
Propeller.  Trans.  Am.  Soc.  of  Me- 
chanical Engineers,  1893,  Vol.  14,  p.  65. 

The  Analysis  of  Certain  Curves  arising  in 
Engineering  Investigation.  Jour,  of 
Am.  Soc.  of  Naval  Engineers,  1893, 
Vol.  5,  p.  543. 

On  the  Law  of  Frictional  Resistance. 
Trans,  of  Am.  Soc.  of  Naval  Architects 
and  Marine  Engineers,  1893,  Vol.  1,  p. 
210. 

A  Planimeter  for  Averaging  Radial  Ordi- 
nates.  Sibley  Jour,  of  Eng.  1893, 
Vol.  7,  p.  64. 

Uses  of  Logarithmic  Paper.  Engineering 
News,  Sept.  28,  1893, 

New  Rules  for  Approximate  Integration. 
Ibid.,  Jan.  18,  1894, 


490 


Titles  of 


Mathematical  Treatment  of  Continuous 
Functions  by  Approximate  Methods. 
Sibley  Jour,  of  Eng.,  Jan.,  1894,  Vol. 

8,  p.  135. 

An  Approximate  Formula  for  the  Wetted 
Surface  of  Ships.  (With  G.  R.  McDer- 
mott).  Trans.  Am.  Soc.  of  Naval 
Architects  and  Marine  Engineers,  1894, 
Vol.  2,  p.  297. 

Water  Tube  Boilers  for  Marine  Purposes, 
Sibley  Jour,  of  Eng.,  Feb.,  1895,  Vol. 

9,  p.  181. 

Electricity  for  Marine  Propulsion.  Cas- 
sier's  Magazine,  Jan.,  1895,  Vol.  8, 
p.  143. 

Curves  showing  the  Relation  between 
Equivalent  Hollow  and  Solid  Shafts. 
Jour,  of  Am.  Soc.  of  Naval  Engineers, 
1895,  p.  507. 

The  Number  of  Longitudinal  Intervals  in 
Ship  Computations  as  Affecting  the 
Accuracy  of  Integration  for  Displace- 
ment. Trans.  Am.  Soc.  of  Naval 
Arcliitects  and  Marine  Engineers,  1895, 
Vol.  3,  p.  129. 

Note  on  Different  Forms  of  the  Entropy 
Function.  Physical  Bevieio,  Vol.  4, 
p.  343. 

Determination  of  the  Current  Curve  Cor- 
responding to  any  Form  of  Alternating 
Electromotive  Force  in  a  Circuit  with- 
out Iron.  Sibley  Jour,  of  Eng.,  1897, 
p.  182. 

Method  of  Determining  a  Continuous 
Record  of  the  Performance  of  a  Marine 
Engine.  Jour.  Am.  Soc.  of  Naval 
Engineers,  1897,  p.  1. 

Graphical  Determination  of  the  Index  of 
the  Power  according  to  which  one 
quantity  varies  relative  to  another. 
Jour,  of  Franklin  Inst.,  March, 
1897. 

An  Experimental  Study  of  the  Influence 
of  Surface  on  the  Performance  of  Screw 
Propellers.  Trans.  Am.  Soc.  of  Naval 
Architects  arid  Marine  Engineers,  Vol. 
5,  p.  107. 

Steamship  Vibrations  and  the  Balancing 
of  Marine  Engines.  Marine  Engineer- 
ing, June,  July,  August,  1897. 

Resistance    and    Propulsion     of     Ships. 


J.  Wiley  &  Sons,  New  York,  1898.  vs.. 
+  431  pp. 

The  Approximate  Treatment  of  Differen- 
tial Equations.  Annals  of  Math.,  July, 
1898,  p.  110. 

Entropy  and  Temperature  Entropy  Dia- 
grams. Jour.  Soc.  Naval  Engineers, 
1898,  p.  329. 

Electrical  Propulsion  for  Torpedo  Boats. 
Ibid.,  1899,  p.  53. 

FREDERICK    EBY:  — 

A.B.,  McMaster  University,  1895;  Gradu- 
ate Student,  University  of  Chicago,  1895- 
97  ;  Assistant  Instructor,  Morgan  Park 
Academy,  Morgan  Park,  111.,  1897-98; 
Scholar  in  Pedagogy,  Clark  Univer- 
sity, 1898-99. 

Author  of :  — 

Suggestions  for  Work  which  can  be  done 
by  Teachers.  43d.  Anriual  Report 
State  Supt.  of  Ed.,  Albany,  N.  Y., 
1897,  Vol.  2,  pp.  968-972. 

Study  of  the  Use  of  Secret  Languages 
(Syllabus).     Ibid.,  pp.  972-973. 

Preliminary  Study  of  Child-^^sthetics 
(Syllabus).     Ibid.,  p.  976. 

Educational  Value  of  Manual  Construc- 
tive Work.  Education,  April,  1898, 
Vol.  18,  pp.  491-495. 

Translation  of  Pestalozzi's  "Meine  Nach- 
forschungen."  (With  Dr.  Julia  E. 
Bulkley.)     (In  press.) 

THOMAS  "W.  EDMONDSON:  — 

B.A.,  London,  Eng.,  1888  (first  in  Honors 
and  Senior  Exhibitioner  at  Matriculation, 
June,  1886)  ;  Akroyd  Scholar,  1888-90  ; 
Senior  Mathematical  Scholar,  Pembroke 
College,  Cambridge  University,  Eng., 
1888-91  ;  B.A.,  Cambridge  University 
(18th  Wrangler  in  Mathematical  Tripos), 
1891 ;  Graduate  Student  in  Chemistry, 
Physics,  and  Botany,  ibid.,  1891  ;  Assist- 
ant Tutor  in  Mathematics  and  Physics, 
University  Corr.  College,  Cambridge,  Eng., 
1889-93 ;  First  Class  in  Intermediate 
Science  Examination,  London,  1893 ; 
Fello-w  in  Physics,  Clark  University, 
1894-96;    Ph.D.,    Clark    University, 


Published  Peepers. 


491 


1896 ;  Assistant  Professor  of  Physics, 
New  York  University,  1896- ;  Member  of 
the  American  Mathematical  Society,  and 
American  Physical  Society. 

Author  of :  — 

Key  to  Briggs  and  Bryan's  Coordinate 
Geometry.  W.  B.  Clive  &  Co., 
London,  New  York,  and  Sydney,  1891. 
192  pp. 

"Worked  Examples  in  Coordinate  Geome- 
try. W.  B.  Clive  &  Co.,  London,  New 
York,  and  Sydney,  1891 ;  18  Exam. 
Papers  +  62  pp. 

Mensuration  and  Spherical  Geometry. 
(In  collaboration  with  W.  Briggs, 
M.A.,  LL.B.,  etc.)  W.  B.  Clive  & 
Co.,  London,  New  York,  and  Sydney, 
1893.     vi.  +112,  ii.  +48  pp. 

Key  to  Briggs  and  Bryan's  Elementary 
Text-book  of  Mechanics.  (In  collab- 
oration with  Bion  Eeynolds,  M.A.) 
W.  B.  Clive  &  Co. ,  London,  New  York, 
and  Sydney,  1895.    viii.  +  172  pp. 

On  the  Disruptive  Discharge  in  Air  and 
Liquid  Dielectrics.  Physical  Beview, 
Feb.,  1898,  Vol.  6,  pp.  65-97. 

CHARLES   L.  EDWARDS:  — 

B.S.,  Lombard  University,  1884;  B.S., 
Indiana  University,  1886 ;  A.M.,  ibid., 
1887  ;  Student,  Johns  Hopkins  University, 
1887-89;  Ph.D.,  University  of  Leipzig, 
1890 ;  Fellow  in  Morphology,  Clark 
University,  1890-91 ;  Honorary  Fel- 
low, Clark  University,  1891-92; 
Assistant  Professor  of  Biology,  University 
of  Texas,  1892-93  ;  Adjunct  Professor  of 
Biology,  ibid.i  1893-94;  Professor  of 
Biology,  University  of  Cincinnati,  1894- ; 
Member  of  the  American  Society  of  Natu- 
ralists ;  Morphological  Society  ;  President 
of  the  American  Folk-Lore  Society,  1899 ; 
Socio  Corresponsal,  La  Sociedad  de  Geo- 
grafia  y  Estadistica,  Mexico ;  Socio 
Honorario,  La  Sociedad  Mexicana  de 
Historia  Natural ;  Socio  Honorario,  La 
Sociedad  Antonio  Alzate. 

Author  of :  — 

The  Relation  of  the  Pectoral  Muscles  in 
Birds  to  the  Power  of  Flight.     Ameri- 


can Naturalist,  Jan.,  1886,  Vol.  20, 
pp.  25-29. 

A  Review  of  the  American  Species  of  the 
Tetraodontidse.  (With  President  David 
S.  Jordan.)  Proc.  of  U.  S.  Nat.  Mus., 
1886,  p.  232. 

The  Influence  of  Warmth  upon  the  Irrita- 
bility of  Frog's  Muscle  and  Nerve. 
Studies  from  Biol.  Lab.,  Johns  Hop- 
kins University,  July,  1887. 

Winter  Roosting  Colonies  of  Crows.  Am. 
Jour,  of  Psy.,  May,  1888,  Vol.  1,  pp. 
436-459. 

Notes  on  the  Embryology  of  Miilleria 
Agassizii  Sel. ,  a  Holothurian  common 
at  Green  Turtle  Bay,  Bahamas.  Johns 
Hopkins  University  Circular,  1889, 
Vol.  8,  p.  37. 

Folk-Lore  of  the  Bahama  Negroes.  Am. 
Jour,  of  Psy.,  Aug.,  1889,  Vol.  2,  pp. 
619-542. 

Beschreibung  einiger  neuen  Copepoden 
und  eines  neuen  copepodenahnlichen 
Krebses,  Leuckertella  paradoxa. 
Archiv  f.  Naturrjeschichte,  Berlin, 
1891,  Jahrg.  67,  Bd.  1,  36  pp. 

Some  Tales  from  Bahama  Folk-Lore. 
Jour,  of  Am.  Folk-Lore,  1891,  Vol.  4, 
pp.  47-54. 

Some  Tales  from  Bahama  Folk-Lore. 
Fairy  Tales:     Ibid.,  pp.  247-252. 

Bahama  Songs  and  Stories.  (Vol.  3  of 
Memoirs  of  the  Am.  Folk-Lore  Society.) 
Houghton,  Mifflin  &  Co.,  Boston,  1895. 
Ill  pp. 

Notes  on  the  Biology  of  Phrynosoma  Cor- 
nutum  Harlan.    Zool.  Atizeiger,  1896. 

STAFFORD    C.    EDWARDS:  — 

Classical  Graduate,  Oneonta,  N.  Y., 
Normal,  1891  ;  A.B.,  Brown  University, 
1895;  A.M.,  Philosophy  and  Pedagogy, 
ibid.,  1896  ;  Student  Teacher  of  History  and 
English,  High  School,  Providence,  R.  I., 
1895-96;  Principal  of  Greenport,  N.  Y., 
Union  School,  1896-97  ;  Scholar  in 
Pedagogy,  Clark  University,  Oct., 
1897-March,  1898  ;  Teacher  of  Mathe- 
matics, Jamaica,  N.  Y.,  Normal  School, 
March-June,  1898 ;  Principal  Union  School, 
Schuylerville,  N.  Y.,  1898-. 


492 


Titles  of 


ALEXANDER   CASTVELL   ELLIS:  — 

Head  Master,  Classical  High  School, 
Chapel  Hill,  N.  C,  1891-92;  A.B., 
University  of  North  Carolina,  1894 ; 
Scholar  in  Pedagogy,  Clark  Univer- 
sity, 1894-95  ;  Fellow  in  Psychology, 
1895-97;  Ph.D.,  Clark  University, 
1897  ;  Adjunct  Professor  of  Pedagogy, 
University  of  Texas,  1897- ;  Member  of 
American  Association  for  the  Advance- 
ment of  Physical  Education ;  Member 
of  Illinois  Child-Study  Society ;  Fellow, 
Texas  Academy  of  Science. 

Author  of  :  — 

Sunday  School  Work  and  Bible  Study  in 
the  Light  of  Modern  Pedagogy.  Peda- 
gogical Seminary,  June,  1896,  Vol.  3, 
pp.  363-412. 

A  Study  of  Dolls.  (With  G.  Stanley  Hall. ) 
Ihid.,  Dec,  1896,  Vol.  4,  pp.  129-175. 

Suggestions  for  a  Philosophy  of  Education. 
Ihid.,  Oct.,  1897,  Vol.  5,  pp.  159-201. 

Play  in  Education.  Northxoestern  Monthly, 
Nov.,  1898  ;  and  Bep.  of  Ad.  and  Proc. 
Texas  State  Teachers''  Ass^n,  1898. 

Reading  and  Literature  in  the  Schools. 
Bep.  of  Ad.  and  Proc.  Texas  State 
Teachers'  Ass'ti,  18'98. 

The  Science  of  Education  in  the  Univer- 
sity of  Texas,  and  Some  of  Its  Prob- 
lems. University  Becord,  University 
of  Texas,  Vol.  1,  No.  2. 

BENJAMIN    F.    ELLIS:  — 

A.B.,  Dartmouth  College,  1889  ;  Instruc- 
tor in  Physics  and  Mathematics,  High 
School,  Peoria,  111.,  1889-92  ;  Scholar  in 
Physics,  Clark  University,  1892-93  ; 
Instructor,  High  School,  Peoria,  111., 
189:3-. 

PERCY  NORTON   EVANS:  — 

B.A.Sc,  McGill  University,  Montreal, 
1890  ;  Assistant  in  Chemistry,  ibid.,  1890- 
91 ;  Student,  University  of  Leipzig  (McGill 
Exhibition  of  1851  Science  Scholar),  1891- 
98  ;  Ph.D.,  University  of  Leipzig,  1893  ; 
Honorary  Fello-w  in  Chemistry,  Clark 
University,  1894  ;  Assistant  in  Chemis- 
try to  Professor  Atwater,  Wesleyan  Uni- 


versity, 1894-95  ;  Instructor  in  Chemistry, 
Purdue  University,  1895-96 ;  Associate 
Professor  of  Chemistry,  ibid.,  1896- ; 
Member  of  the  Indiana  Academy  of 
Science. 

Author  of :  — 

Condensation  von  /3-Diketonen  mit  Harn- 
stoff  und  Thioharnstoff.  Jour,  fur 
praktische  Chemie,  Vol.  46,  p.  352. 

Condensationsprodukte  der  /3-Diketone 
mit  Harnstoff,  Guanidin,  und  Thioharn- 
stoff.    Ibid.,  Vol.  48,  pp.  489-517. 

Food  Adulteration.  Purdue  University 
Monographs,  1896.     17  pp. 

An  Introductory  Course  in  Quantitative 
Analysis.  Ginn  &  Co.,  Boston,  1897. 
iv. +  83  pp. 

Note  on  Some  Combustion  Products  of 
Natural  Gas.  Proc.  Ind.  Acad,  of 
Science,  1897,  pp.  133-134. 

Note  on  the  Iodine  Number  of  Linseed 
Oil.     Ibid.,  1898,  pp.  160-163. 

H.   L.   EVERETT:  — 

A.B.,  Brown  University,  1886;  A.M., 
Harvard  University,  1889  ;  Student,  Berlin 
University,  1889-90;  Professor,  Utah 
Agricultural  College,  1890-92  ;  Scholar 
in  Psychology,  Clark  University, 
1896-97  ;  Honorary  Fellov^  in  Psy- 
chology, 1897-98 ;  Instructor,  Macken- 
zie College,  S.  Paulo,  Brazil,  1898-. 

ALBERT  C.  EYCLESHYMER  : — 

Assistant  in  Animal  Morphology,  Uni- 
versity of  Michigan,  1888-89  ;  Assistant 
in  Botany,  ibid.,  1889-90  ;  Chief  Assist- 
ant, Allis  Lake  Laboratory,  1890-91  ; 
B.S.,  University  of  Michigan,  1891  ; 
Fellow  in  Morphology,  Clark  Uni- 
versity, 1891-92  ;  Fellow  in  Biology, 
University  of  Chicago,  1892-93  ;  Assistant 
in  Anatomy  and  Histology,  ibid.,  189.3- 
95;  Ph.D.,  University  of  Chicago,  1895; 
Tutor  in  Anatomy  and  Histology,  ibid., 
1895-. 

Author  of :  — 

Celloidin  Imbedding  in  Plant  Histology. 
Botanical  Gazette,  Vol.  15,  pp.  272- 
295. 


Published  Papers. 


493 


Notes  on  Celloidin  Technique.  American 
Naturalist,  Vol.  26,  pp.  354-358. 

Club-root  (Plasmodiophora  brassicae 
Wor.)  in  the  United  States.  Journal 
of  Mycology,  Vol.  7,  pp.  79-90. 

Paraphysis  and  Epiphysis  in  Amblystoma. 
Anatomischer  Anzeiger,  April  7,  1892, 
Vol.  7,  pp.  215-217. 

The  Cleavage  of  the  Amphibian  Ovum. 
(With  E.  O.  Jordan.)     Ibid.  Sept.  15, 

1892,  Vol.  7,  pp.  622-624. 

The  Development  of  the  Optic  Vesicles  in 
Amphibia.     Jour,   of  Morph.,  April, 

1893,  Vol.  8,  pp.  189-194  ;  Figs.  1-6. 
On    the    Cleavage    of    Amphibian    Ova. 

(With  E.    0.   Jordan.)     Ibiil,  Sept., 

1894,  Vol.  9,  pp.  407-416  ;  PI.  xxvi. 
The  Early  Development  of  Amblystoma 

with  Observations  on  some  other 
Vertebrates.  Ibid.,  Feb.,  1895,  Vol. 
10,  pp.  343-418  ;  Pis.  xviii-xxii. 

FREDERICK  C.  FERRY  :  — 

A.B.,  Williams  College,  1891;  Instructor 
in  Latin  and  Mathematics,  ibid.,  1891- 
94;  A.M.,  ibid.,  1894  ;  Graduate  Student 
in  Mathematics,  Harvard  University, 
1894-95;  A.M.,  ibid.,  1895;  Fellow  in 
Mathematics,  Clark  University,  1895- 
98;  Ph.D.,  Clark  University,  1898; 
Assistant  Professor  of  Mathematics,  Wil- 
liams College,  1899-. 

Author  of :  — 

Geometry  on  the  Cubic  Scroll  of  the  First 
Kind.  Archiv  for  Mathematik  og  Na- 
turvidenskab,  B.  xxi,  Nr,  2. 

DANIEL   FOLKMAR:  — 

A.B.,  Western  College,  1884  ;  A.M.,  ibid., 
1888  ;  Student,  Harvard  Divinity  School, 
1888-89  ;  Fellow  in  Psychology,  Clark 
University,  1889-90  ;  Professor  of  Po- 
litical Science  and  Psychology,  Indiana 
Normal  University,  1890-91  ;  President 
and  Professor  of  Social  Science,  ibid., 
1891-92 ;  Professor  of  Social  Science, 
Western  Michigan  College,  1892-93  ;  Presi- 
dent, ibid.,  1893  ;  Lecturer  in  Sociology, 
University  of  Chicago,  1893-95  ;  Professor 
of  Psychology  and  Pedagogy,  State  Nor- 


mal School,  Milwaukee,  Wis.,  1895-98  ; 
Student,  University  of  Paris,  1898-99; 
Professor  of  Anthropology,  University 
Nouvelle,  Brussels,  Belgium,  1898  ;  Doc- 
teur  fes  sciences  sociales,  ibid.,  June,  1899  ; 
Fellow  of  the  Royal  Statistical  Society, 
London  ;  Member  of :  Anthropologische 
Gesellschaft  in  Wien,  Anthropological  So- 
ciety of  Washington,  American  Associa- 
tion for  the  Advancement  of  Science, 
American  Academy  of  Political  and  Social 
Science,  American  Statistical  Association, 
American  Institute  of  Sociology,  Wisconsin 
Academy  of  Sciences,  Arts,  and  Letters. 

Author  of :  — 

Instruction  in  Sociology  in  Institutions  of 
Learning.  Reprint  from  Proc.  of  Nat. 
Conf.  of  Charities  and  Correction, 
Boston,  1894.  19  pp.  Also  reprinted 
as  Chapter  XXVII  of  the  Report  of 
U.  S.  Com.  of  Ed.  for  1894-95,  Vol.  2, 
pp.  1211-1221. 

A  Sociological  Ideal  View  of  Normal 
Schools.  Proc.  of  Inter.  Cong,  of  Ed. 
of  the  World's  Columbian  Exposition, 
1893,  pp.  422-428.  Published  by  Am, 
Ed.  Ass'n,  New  York,  1893. 

New  Views  in  Social  Science,  etc.  The 
Interrogator,  Feb. -June,  1893. 

The  Ideal  in  Professional  Training."  Edu- 
cation, April,  1896. 

The  Duration  of  School  Attendance  in 
Chicago  and  Milwaukee.  Proc.  Wis- 
consin  Academy  of  Sciences,  Arts,  and 
Letters,  1897,  Vol.  12,  pp.  255-305. 

Anthropology,  not  Sociology,  as  an  ade- 
quate Philosophy  of  Human  Life. 
Proc.  A.  A.  A.  8.,  1898. 

Sociology  as  based  upon  Anthropology. 
Am.  Jour,  of  Soc.  Sci.,  1898. 

Anthropologic  Philosophique.    (In  press.) 

CLEMENS   JAMES   FRANCE:  — 

A.B.,  Hamilton  College,  1898;  Scholar 
in  Psychology,  Clark  University, 
1898-99. 

Author  of:  — 

The  Psychology  of  Ownership.  (With 
L.  W.  Kline.)  Pedagogical  Seminary. 
(In  press.) 


494 


Titles  of 


JOSEPH  IRWIN  FRANCE:  — 

A.B.,  Hamilton  College  (Root  Scientific 
Fellowship,  with  Honors  in  Biology), 
1895 ;  Student,  University  of  Leipzig, 
1895-96  ;  Scholar  in  Psychology,  Clark 
University,  1896-97  ;  A.M.  (honorary), 
Hamilton  College,  1898  ;  Supervisor  and 
Instructor  in  Science,  Jacob  Tome  Insti- 
tute, Port  Deposit,  jMd.,  1897- ;  Student, 
College  of  Physicians  and  Surgeons,  Balti- 
more. Md.,  1898-99. 

Author  of :  — 

The  Conservation  of  Cosmos.     An  Essay. 

Gressner  &  Schramm,  Leipzig,   1896. 

18  pp. 
Nature-Study.        Educational       Beview, 

March,  1899,  Vol.  17,  pp.  292-295. 

ALEXANDER  FRASER :  — 

A.B.,  Dalhousie  College,  1889;  Graduate 
Student,  Harvard  University,  1889-90; 
Fellow  in  Psychology,  Clark  Uni- 
versity, 1891-92  ;  Student  in  Medicine, 
Dalhousie  University,  1893-97 ;  M.D., 
CM.,  ibid.,  1897  ;  Lecturer  in  Psychology, 
Halifax  Ladies'  College,  1893-94;  In- 
structor in  Psychology,  Halifax  School  for 
the  Blind,  1894-95  ;  House  Surgeon,  Vic- 
toria General  Hospital,  Halifax,  N.  S., 
1897-98 ;  Practising  Physician  and  Sur- 
geon, New  Glasgow,  N.  S.,  1898-. 

Author  of : — 

Visualization  as  a  Chief  Source  of  the  Psy- 
chology of  Hobbes,  Locke,  Berkeley, 
and  Hume.  Am.  Jour,  of  Fsy.,  Dec, 
1891,  Vol.4,  pp.  230-247. 

The  Psychological  Foundation  of  Natural 
Realism.  Ibid.,  April,  1892,  Vol.  4, 
pp.  429-450. 

The  Psychological  Basis  of  Hegelism. 
Ibid.,  July,  1893,  Vol.  5,  pp.  472-495. 

JOHN  S.  FRENCH  :  — 

A.B.,  Bowdoin  College,  1895;  Scholar 
in  Mathematics,  Clark  University, 
1895-96;    Fellow,    1896-98;    Ph.D., 

Clark  University,  1898  ;  Supervisor  and 
Instructor  in  Mathematics,  Jacob  Tome 
,  Institute,  1898-. 


Author  of :  — 

On  the  Theory  of  the  Pertingents  to  a 
Plane  Curve.     (In  press. ) 

JOHN  PHELPS  FRUIT  :  — 

A.B.,  Bethel  College,  Ky.,1878;  Instruc- 
tor  of  Latin  and  Mathematics,  High 
School,  Parker's  Grove,  Ky.,  1878-79 ; 
Professor  of  Latin  and  Greek,  Bardstown 
Institute,  Ky.,  1879-81  ;  A.M.,  Bethel 
College,  1881  ;  President,  Liberty  Female 
College,  Glasgow,  Ky.,  1881-83  ;  Professor 
of  English  Literature,  Bethel  College, 
188:3-97  ;  Scholar  in  Psychology,  Clark 
University,  1891 ;  Graduate  Student, 
University  of  Leipzig,  1894-95;  Ph.D., 
University  of  Leipzig,  1895  ;  Professor  of 
English  Language  and  Literature,  William 
Jewell  College,  1897-;  Memberof :  Modern 
Language  Association,  American  Dialect 
Society,  American  Statistical  Association, 
Southern  History  Association. 

Author  of :  — 

The  Evolution  of  Figures  of  Speech. 
Modern  Language  Notes,  Dec,  1888. 

Browning  and  Tennyson.  Ibid.,  May, 
1890. 

A  Plea  for  the  Study  of  Literature  from 
the  -Esthetic  Standpoint.  Pub.  of  the 
Modern  Language  Ass''n,  1891,  Vol.  6, 
No.  1. 

Shakespeare's  Egoism.  Poet  Lore,  Sept., 
1899,  Vol.  1,  pp.  406-407. 

The  Destiny  of  Marriage  :  Portia  and  the 
Caskets.  Ibid.,  Feb.,  1891,  Vol.  3, 
pp.  69-74. 

Uncle  Remus  in  Phonetic  Spelling.  Dia- 
lect Notes,  Boston,  1892,  Part  4,  pp. 
196-198. 

The  Ideal  the  Need  of  the  People.  Soxith- 
ern  Magazine,  May,  1894. 

John  Milton.  Seminary  Magazine  (Louis- 
ville, Ky.),  March,  1899. 

The  Mind  and  Art  of  Poe's  Poetry.  A.  S. 
Barnes  &  Co.,  New  York,  1899.  144  pp. 

HOMER   GAGE:— 

A.B.,  Harvard  University,  1882;  A.M., 
ibid.,  1887;  M.D.,  ibid.,  1887;  Physician 
and   Surgeon,  Worcester,  Mass.,   1888- ; 


Published  Pampers. 


495 


Honorary  Scholar  in  Anatomy,  Clark 
University,  1889-90  ;  Surgeon  to  Me- 
morial, St.  Vincent,  and  Worcester  City- 
Hospitals  ;  Consulting  Surgeon  to  Baldwin- 
ville  Cottage  Hospital. 

BENJAMIN  IVES  GILMAN  : — 

A.B.,  Williams  College,  1872;  A.M., 
ibid.,  1880;  Fellow,  Johns  Hopkins  Uni- 
versity, 1881-83 ;  Lecturer  at  Princeton, 
Harvard,  and  Columbia,  1890-91  ;  In- 
structor in  Psychology,  Clark  Uni- 
versity, 1892-93  ;  Curator,  Museum  of 
Fine  Arts,  Boston,  Mass.,  1893-. 

Author  of:  — 

On  Propositions  and  the  Syllogism.  On 
Propositions  called  Spurious.  J.  H. 
U.  Circular,  Aug.,  1882,  pp.  240-241. 

On  Operations  in  Relative  Number.  Johns 
Hopkins  Studies  in  Logic,  1882. 

A  Study  of  the  Inductive  Theories  of 
Bacon,  Whewell,  and  Mill.  Colorado 
College  Studies,  1890,  pp.  17-26. 

Zuni  Melodies.  Jour,  of  Am.  Arch,  and 
Eth.,  Vol.  1,  1891,  pp.  65-91. 

On  some  Psychological  Aspects  of  the 
Chinese  Musical  System.  Philosophi- 
cal Bevieio,  Jan.  and  March,  1892,  Vol. 
1,  pp.  54-71,  154-178. 

On  the  Properties  of  a  One-dimensional 
Manifold.  3Iind,  Oct.,  1892,  N.  S., 
Vol.  1,  pp.  518-526. 

Report  on  an  Experimental  Test  of  Musi- 
cal Expressiveness.  Am.  Jour,  of  Psy., 
Vols.  4  and  5,  Aug.  and  Oct.,  1892. 

Syllabus  of  Lectures  on  the  Psychology  of 
Pain  and  Pleasure.  Ibid.,  Oct.,  1893, 
Vol.  6,  pp.  3-60. 

HENRY   H.   GODDARD:— 

A.B.,  Haverford  College,  1887;  A.M., 
ibid.,  1889  ;  Instructor  in  Latin  and  His- 
tory, University  of  Southern  California, 
1887-88  ;  Graduate  Student,  Haverford 
College,  1888-89 ;  Principal,  Damascus 
Academy,  Ohio,  1889-91 ;  Instructor  in 
Latin  and  Greek,  Oak  Grove  Seminary, 
Vassalboro,  Me.,  1891-93 ;  Principal,  ibid., 
1893-96  ;  Scholar  in  Psychology,  Clark 
University,  1896-97  ;    Fellow,  1897- 


99 ;    Ph.D.,  Clark  University,  1899  ; 

Professor  of  Psychology  and  Pedagogy, 
State  Normal  School,  West  Chester,  Pa., 
1899-. 

Author  of :  — 

The  Effects  of  Mind  on  Body  as  evidenced 
by  Faith  Cures.  Am.  Jour,  of  Psy., 
April,  1899,  Vol.  10,  pp.  431-502. 

JOHN   H.  GRAY,  JR.— 

B.S.,  University  of  California,  1887;  As- 
sistant to  State  Analyst,  California,  1887- 
90 ;  Assistant  in  Chemistry,  University 
of  California,  1889-90  ;  Instructor  in 
Chemistry,  ibid,  1890-92 ;  Fellow  in 
Chemistry,    Clark  University,    1892- 

94  ;  Instructor  in  Physics  and  Chemistry, 
State  Normal  School,  Chico,  Cal.,  1894- 

95  ;  Assistant  in  Chemistry,  University  of 
California,  1895-96  ;  Instructor  in  Chem- 
istry, ibid.,  1896-. 

CEPHAS   GUILLBT:  — 

A.B.,  Victoria  University,  Cobourg, 
Ont.  (Honors  in  English,  French  and 
German  Literature),  1887  ;  Modern  Lan- 
guage Master,  Perth,  Ont. ,  1887-90  ; 
Modern  Language  Master,  Ottawa,  Ont., 
1890-94  ;  Student  at  Law,  Osgoode  Hall, 
Toronto,  1894-95 ;  Scholar  in  Psy- 
chology, Clark  University,  1895-96  ; 
Fellow,  1896-98. 

R.  R.  GURLEY:  — 

United  States  Naval  Academy,  1877-79 ; 
Assistant  Resident  Physician,  Children's 
Hospital,  Washington,  D.  C,  1882-84  ; 
M.D.  (First  Honor),  National  Medical 
College,  Washington,  D.  C,  1884  ;  Resi- 
dent Physician,  United  States  Soldiers' 
Home  Hospital,  Washington,  D.  C,  1884- 
85 ;  Scientific  Assistant,  United  States 
National  Museum,  Washington,  D.  C, 
1886-90 ;  Scientific  Assistant,  Biological 
Laboratory,  United  States  Fish  Com- 
mission, Washington,  D.  C,  1890-95  ;  M. 
Sc,  Columbian  University,  1895  ;  Fellow 
in  Biology,   Clark  University,   1895- 

96  ;  Junior  Assistant  Physician,  Worcester 
Insane  Hospital,  1896-97  ;  Assistant  Phy- 
sician, ibid.,  1897-. 


496 


Titles  of 


Author  of:  — 

The  Geologic  Age  of  the  Graptolite 
Shales  of  Arkansas.  Ann.  Bep.  Geol. 
Survey,  Arkansas,  1890,  Vol.  3,  pp. 
401-418,  PI.  9. 

Some  Recent  Graptolite  Literature. 
American  Geologist,  1891,  pp.  35-43. 

The  Classification  of  the  Myxosporidia, 
a  Group  of  Protozoan  Parasites  infest- 
ing Fishes.     Bull.   U.  8.  Fish  Com., 

1891,  pp.  407-420. 

The  Myxosporidia,  or  Psorosperms  of 
Fishes,  and  the  Epidemics  produced 
by  them.      Rep.    U.    S.   Fish.    Com., 

1892,  pp.  65-304,  PI.  1-47. 

The  North  American  Graptolites.  Journal 
of  Geology,  1896,  Vol.  4,  pp.  63-102 ; 
291-311.     PI.  4-5. 

G.  STANLEY  HALL  : — 

A.B.,  Williams  College,  1867;  A.M., 
1870  ;  Union  Theological  Seminary,  N.  Y., 
1867-68  ;  Universities  Berlin  and  Bonn, 
1869-70 ;  Union  Theological  Seminary, 
N.  Y.,  1870-71;  Universities  of  Berlin 
and  Heidelberg,  1871-72 ;  Professor  of 
Philosophy,  Antioch  College,  1872-76; 
Instructor,  Harvard  University,  1876-78  ; 
Ph.D.,  Harvard  University,  1878;  Uni- 
versitieb  of  Berlin  and  Leipzig,  1878-80 ; 
Lecturer  in  Harvard  University  and 
Williams  College,  1880-81  ;  Professor  of 
Psychology,  Johns  Hopkins  University, 
1881-88  ;  LL.D.,  University  of  Michigan, 
1888,  and  Williams  College,  1889 ;  Presi- 
dent, and  Professor  of  Psychology, 
Clark  University,  1888- ;  Editor  and 
Founder  of  American  Journal  of  Psychol- 
ogy (Founded  in  1887),  and  Pedagogical 
Seminary  (Founded  in  1891)  ;  Resident 
Fellow  of  the  American  Academy  of  Arts 
and  Sciences ;  Resident  Member  of  the 
Massachusetts  Historical  Society  ;  Mem- 
ber of  American  Antiquarian  Society. 

Author  of :  — 

John  Stuart  Mill.  Williams  Quarterly, 
Williamstown,  Mass.,  Aug.,  1867. 

Digest  of  Dorner's  Theology.  Presby- 
terian Revieio,  Jan.,  1873,  pp.  60-93. 

Hegel  as  the  National  Philosopher  of  Ger- 


many. (Translated  from  the  German 
of  Dr.  Carl  Rosenkranz. )  Gray,  Baker, 
&  Co.,  St.  Louis,  1874.     159  pp. 

Hegel :  His  Followers  and  Critics.  Jour, 
of  Spec.  Philos.,  1878,  Vol.  12,  pp.  93- 
103. 

Color  Perception.  Proc.  Am.  Acad,  of 
Arts  and  Sciences,  March,  1878,  Vol. 
3,  pp.  402-413. 

The  Muscular  Perception  of  Space.  Mind, 
Oct.,  1878,  Vol.  3,  pp.  433-450. 

The  Philosophy  of  the  Future.  Nation, 
Nov.  7,  1878,  Vol.  27,  pp.  283-284. 

Philosophy  in  the  United  States.  Mind, 
Jan.,  1879,  Vol.  4,  pp.  89-105;  also 
Pop.  Sci.  Mo.,  Suppl.  No.  1,  1879,  p.  57. 

Ueber  die  Abhangigkeit  der  Reactions- 
zeiten  vom  Ort  des  Reizes.  (With 
J.  V.  Kries.)  Archiv  f.  Physiol.  (Du 
Bois-Reymond),  Suppl.  Band,  1879, 
pp.  1-10. 

Die  willkiirliche  Muskelaction.  (With 
Hugo  Kronecker.)     Ibid.,  pp.  11-47. 

Laura  Bridgman.  3Iind,  April,  1879, 
Vol.  4,  pp.  149-172. 

Recent  Researches  in  Hypnotism.  Ibid., 
Jan.,  1881,  Vol.  6,  pp.  98-104. 

Aspects  of  German  Culture.  James  R. 
Osgood  &  Co.,  Boston,  1881.    320  pp. 

Moral  and  Religious  Training  of  Children. 
Princeton  Review,  Jan.,  1882,  Vol.  10, 
pp.  26-48. 

Chairs  of  Pedagogy  in  our  Higher  Institu- 
tions of  Learning.  N.  E.  A.,  March, 
1882  ;  U.  S.  Bur.  of  Ed.,  Circular  of 
Information,  No.  2,  1882,  pp.  35-44. 

Optical  Illusions  of  Motion.  (With  Dr. 
H.  P.  Bowditch.)   Jour.  ofPhys.,  Aug., 

1882,  Vol.  3,  pp.  297-307. 

The  Education  of  the  Will.  Princeton 
Reviev),  Nov.,  1882,  Vol.  10,  pp.  306- 
325.  Reprinted  in  Pedagogical  Semi- 
nary, June,  1892,  Vol.  2,  pp.  72-89. 

Methods  of  Teaching  History.  (Edited.) 
Ginn,  Heath  &  Co.,  Boston,  1883. 
xii.  4-  296  pp. 

Educational  Needs.     N.  A.  Rev.,  March, 

1883,  Vol.  136,  pp.  284-290. 
Reaction-Time  and  Attention  in  the  Hyp- 
notic State.    Mind,  April,  1883,  Vol.  8, 
pp.  170-182. 


Published  Papers. 


497 


Contents  of  Children's  Minds  on  entering 
School.  Princeton  Beview,  May,  1883, 
Vol.  11,  pp.  249-272;  Pedagogical 
Seminary,  June,  1891,  Vol.  1,  pp.  ISO- 
ITS.  Issued  in  pamphlet  form  by 
E.  L.  Kellogg  &  Co.,  New  York,  1893. 
56  pp. 

Education  and  Theology.  Nation,  July 
26,  1883,  Vol.  37,  pp.  81-82. 

The  Study  of  Children.  (Privatelyprinted.) 
N.  Somerville,  Mass.,  1883,  13  pp. 

Report  of  the  Visiting  Committee  of  the 
Alumni  of  Williams  College,  Williams- 
town,  Mass.,  1884.     11  pp. 

Bilateral  Asymmetry  of  Function.  (With 
E.  M.  Hartwell.)  Mind,  Jan.,  1884, 
Vol.  9,  pp.  93-109. 

New  Departures  in  Education.  N.  Am. 
Bev.,  Feb.  1885,  Vol.  140,  pp.  144- 
152. 

The  New  Psychology.  Andover  Beview, 
Feb.  and  March,  1885,  Vol.  3,  pp.  120- 
135,  239-248.  Opening  lecture,  Johns 
Hopkins  University,  Oct. ,  1884, 

Experimental  Psychology.  Mind,  April, 
1885,  Vol.  10,  pp.  245-249. 

Children's  Collections.  Nation,  Sept.  3, 
1885,  Vol.  41,  p.  190;  reprinted  in 
Pedagogical  Seminary,  June,  1891, 
Vol.    1,   pp.    234-237. 

Overpressure  in  Schools.  Nation,  Oct. 
22,  1885,  Vol.  41,  pp.  338-339. 

Motor  Sensations  of  the  Skin.  (With 
Dr.  H.  H.  Donaldson.)  Mind,  Oct., 
1885,  Vol.  10,  pp.  557-572. 

Studies  of  Rhythm.  (With  Joseph  Jas- 
trow.)  Ihid.,  Jan.,  1886,  Vol.  11,  pp. 
55-62. 

Hints  toward  a  Select  and  Descriptive 
Bibliography  of  Education.  (With 
John  M.  Mansfield.)  D.  C.  Heath  & 
Co.,  Boston,  1886.     309  pp. 

Psychical  Research.  Am.  Jour,  of  Psy., 
Nov.,  1887,  Vol.  1,  pp.  128-146. 

Psychology.  (Reviews.)  Am.  Jour,  of 
Psy.,  Nov.,  1887,  Vol.  1,  pp.  146-164. 

Dermal  Sensitiveness  to  Gradual  Pressure- 
Changes.  (With  Y.  Motora.)  Ibid., 
Nov.,  1887,  Vol.  1,  pp.  72-98. 

The  Story  of  a  Sand  Pile.  Scribner^s 
Magazine,  June,  1888,  Vol.  3,  pp. 
2k 


690-696.  Reprint,  E.  L.  Kellogg  &  Co., 
N.  Y.,  1897.     20  pp. 

Introduction  to  American  Edition  of 
Preyer's  Senses  and  Will.  (Translated 
by  H.  W.  Brown.)     New  York,  1888. 

Address  Delivered  at  the  Opening  of  Clark 
University,  Opening  Exercises,  pp.  9- 
32,  Worcester,  Mass.,  Oct,  2,  1889, 
(Published  by  the  University,) 

A  Sketch  of  the  History  of  Reflex  Action. 
Am.  Jour,  of  Psy.,  Jan.,  1890,  Vol.  3, 
pp.  71-86. 

How  to  teach  Reading,  and  What  to  Read 
in  School.  D.  C.  Heath  &  Co.,  Boston, 
1890.     40  pp.     (First  edition,  1886.) 

Children's  Lies.  Am.  Jour,  of  Psy.,  Jan., 
1890,  Vol.  3,  pp.  59-70.  Reprinted  in 
Pedagogical  Seminary,  June,  1891, 
Vol,  1,  pp.  211-218. 

The  Training  of  Teachers.  Forum,  Sep- 
tember, 1890,  Vol.  10,  pp.  11-22. 

First  Annual  Report  to  the  Board  of 
Trustees  of  Clark  University,  Worces- 
ter, Mass.,  Oct.  4,  1890.     53  pp. 

University  Study  of  Philosophy.  Discus- 
sion. Begents'  Bep.  Univ.,  State  of 
New  York,  1891,  Vol.  105,  pp.  335-338. 

Boy  Life  in  a  Massachusetts  Country  Town 
Thirty  Years  Ago.  Proc.  Am.  Antiq. 
Soc,  Worcester,  Mass.,  1891,  N.  S., 
Vol.  7,  pp.  107-128. 

Educational  Reforms.  Pedagogical  Semi- 
nary, Jan.,  1891,  Vol.  1,  pp.  1-12. 
Appeared  also  as  Riforme  Pedagogiche 
in  II  Bisveglio  Educativo,  Aprile  13- 
16, 1892,  Anno  8,  pp.  207-208,  210-211. 

The  Principles  of  Psychology.  By  William 
James.  (Review.)  Am.  Jour,  of  Psy., 
Feb.,  1891,  Vol.  3,  pp.  578-591. 

Contemporary  Psychologists.  I.  Edward 
Zeller.  Ibid.,  April,  1891,  Vol.  4,  pp. 
156-175. 

Enseignement  des  Sciences.  Bevue  Sci- 
entifique,  April  4,  1891,  Vol.  47,  pp. 
430-433, 

Notes  on  the  Study  of  Infants.  Peda- 
gogical Seminary,  June,  1891,  Vol.  1, 
pp.  127-138. 

The  Moral  and  Religious  Training  of 
Children  and  Adolescents.  Ibid.,  pp. 
196-210. 


498 


Titles  of 


Second  Annual  Report  to  the  Board  of 
Trustees  of  Clark  University,  Worces- 
ter, Mass.,  Sept.  29,  1891.     56  pp. 

The  New  Movement  in  Education.  An 
address  delivered  before  the  School  of 
Pedagogy  of  the  University  of  the  City 
of  New  York,  Dec.  29,  1891.  Pub- 
lished by  the  Women's  Advisory  Com- 
mittee, New  York,  1891.     20  pp. 

The  Outlook  in  Higher  Education.  Acad- 
emy, Boston,  Mass.,  Jan.,  1892,  Vol. 
6,  pp.  543-562. 

Health  of  School  Children  as  affected 
by  School  Buildings.  Beport  of  Proc. 
Dept.  of  Superintendence,  held  in 
Brooklyn,  N.  Y.,  Feb.,  1892,  pp.  163- 
172.  Also  Proc.  N.  E.  A.,  1892,  pp. 
682-691. 

Moral  Education  and  Will  Training. 
Pedagogical  Seminary,  June,  1892, 
Vol.  2,  pp.  72-89. 

Child-study  as  a  Basis  for  Psychology  and 
Psychological  Teaching.  Beport  of 
Com.  0/ £■(?.,  1892-93,  Washington,  D.C., 
1895,  Vol.  1,  pp.  357-358,  366-370. 

Third  Annual  Report  to  the  Board  of 
Trustees  of  Clark  University,  Worces- 
ter, Mass.,  April,  1893.     168  pp. 

Psychological  Progress.  The  Liberal  Club, 
Buffalo,  N.  Y.,  Nov.  16,  1893. 

Child-study  :  The  Basis  of  Exact  Educa- 
tion. Forum,  Dec,  1893,  Vol.  16, 
pp.  429-441. 

American  Universities  and  the  Training 
of  Teachers.  Ibid.,  April,  1894,  Vol. 
17,  pp.  148-159. 

Universities  and  the  Training  of  Pro- 
fessors. Ibid.,  May,  1894,  Vol.  17, 
pp.  297-309. 

Scholarships,  Fellowships,  and  the  Train- 
ing of  Professors.  Ibid.,  June,  1894, 
Vol.  17,  pp.  443-454. 

Research  the  Vital  Spirit  of  Teachmg. 
Ibid.,  July,  1894,  Vol.  17,  pp.  558-570. 

Child-study  in  Summer  Schools.  Begents' 
Bulletin,  University  of  the  State  of 
New  York,  No.  28,  July,  1894.  Albany, 
N.  Y.,  1895,  Vol.  1,  pp.  333-336. 

The  New  Psychology  as  a  Basis  of  Edu- 
cation. Forum,  Augixst,  1894,  Vol.  17, 
pp.  710-720. 


Address  at  the  Bryant  Centennial,  Aug. 
16,  1894.  Bryant  Memorial,  Cum- 
mington,  Mass.,  1894,  pp.  67-69. 

Address.  Dedication  of  the  Hasten  Free 
Public  Library  Building,  North  Brook- 
field,  Mass.,  September  20,  1894.  pp. 
11-21. 

On  the  History  of  American  College  Text- 
Books  and  Teaching  in  Logic,  Ethics, 
Psychology,  and  Allied  Subjects. 
Proc.  Am.  Antiq.  Soc,  Worcester, 
Mass.,  1894,  N.  S.,  Vol.  9,  pp.  137-174. 

Remarks  on  Rhythm  in  Education.  Proc. 
N.  E.  A.,  1894,  pp.  84-85. 

Child-study.     Ibid.,  1894,  pp.  173-179. 

Practical  Child-study.  Jour,  of  Ed.,  Dec. 
13,  1894,  Vol.  40,  pp.  391-392. 

Topical  Syllabi  for  1894-1895.  These 
were  one-  or  two-page  leaflets,  pre- 
pared by  Dr.  Hall,  and  privately  printed 
at  Worcester,  jNIass.  They  covered : 
I.  Anger ;  II.  Dolls  ;  III.  Crying  and 
Laughing  ;  IV.  Toys  and  Playthings  ; 

V.  Folk-Lore      Among      Children ; 

VI.  Early  Forms  of  Vocal  Expres- 
sion;  Vn.  The  Early  Sense  of  Self 

VIII.  Fears  in  Childhood  and  Youth 

IX.  Some  Common  Traits  and  Habits 

X.  Some  Common  Automatisms, 
Nerve  Signs,  etc. ;  XI.  Feeling  for  Ob- 
jects of  Inanimate  Nature  ;  XII.  Feel- 
ing for  Objects  of  Animate  Nature ; 

XIII.  Children's  Appetites  and  Foods ; 

XIV.  Affection  and  its  Opposite  States 
in  Children  ;  XV.  Moral  and  Religious 
Experiences. 

Laboratory  of  the  McLean  Hospital, 
Somerville,  Mass.  Am.  Jour,  of  In- 
sanity, Jan.,  1895,  Vol.  51,  pp.  358- 
364. 

Psychic  Research.  Am.  Jour,  of  Psy., 
Oct.,  1895,  Vol.  7,  pp.  135-142. 

Results  of  Child-study  applied  to  Educa- 
tion. Trans.  III.  Soc.  for  Child-study, 
1895,  Vol.  1,  No.  4,  p.  13. 

Introduction  to  the  Psychology  of  Child- 
hood. By  Frederick  Tracy.  Boston, 
1895. 

Address  at  Union  College  Centennial  An- 
niversary, June  24,  1895.  Printed  by 
the  College.    N.  Y.,  1897,  pp.  230-244. 


Published  Papers. 


499 


Topical  Syllabi  for  1895-96.  I.  Peculiar 
and  Exceptional  Children,  with  E.  W. 
Bohannon ;  II.  Moral  Defects  and 
Perversions,  with  G.  E.  Dawson ;  III. 
The  Beginnings  of  Reading  and  Writ- 
ing, with  Dr.  H.  T.  Lukens ;  IV. 
Thoughts  and  Feelings  about  Old  Age, 
Disease,  and  Death,  with  C.  A.  Scott ; 
V.  Moral  Education,  with  N.  P. 
Avery ;  VI.  Studies  of  School  Read- 
ing Matter,  with  J.  C.  Shaw;  VII. 
Courses  of  Study  in  Elementary  Gram- 
mar and  High  Schools,  with  T.  R. 
Crosswell ;  VIII.  Early  Musical  Mani- 
festations, with  Florence  Marsh;  IX. 
Fancy,  Imagination,  Reverie,  with  E. 
H.  Lindley  ;  X.  Tickling,  Fun,  Wit, 
Humor,  Laughing,  with  Dr.  Arthur 
Allin ;  XI.  Suggestion  and  Imitation, 
with  M.  H.  Small ;  XII.  Religious 
Experience,    with    E.    E.     Starbuck ; 

XIII.  Kindergarten,  with  Miss  Anna 
E.  Bryan  and  Miss  Lucy  Wheelock ; 

XIV.  Habits,  Instincts,  etc.,  in  Ani- 
mals, with  Dr.  R.  R.  Gurley ;  XV. 
Number  and  Mathematics,  with  D.  E. 
Phillips;  XVI.  The  Only  Child  in 
the  Family,  with  E.  W.  Bohannon. 

The  Case  of  the  Public  Schools.  Atlantic 
Monthly,  March,  1896,  Vol.  77,  pp. 
402-413. 

Psychological  Education.  Proc.  of  the 
Am.  Medico-Psychological  Ass^n.  52d 
Annual  Meeting,  Boston,  May  26-29, 
1896,  Transactions,  Vol.  3,  pp.  87- 
100  ;  also,  Am.  Jour,  of  Insanity,  Oct. 
1896,  Vol.  53,  pp.  228-241. 

Generalizations  and  Directions  for  Child- 
study.  Northwestern  Jour,  of  Ed., 
July,  1896,  Vol.  7,  p.  8- 

Address  at  Mount  Holyoke  College, 
Founder's  Day,  Nov.  5,  1896.  Mount 
Holyoke,  S.  Hadley,  Mass.  Nov.,  1896, 
Vol.  6,  pp.  64-71. 

A  Study  of  Dolls.  (With  A.  C.  Ellis.) 
Pedagogical  Seminary,  Dec,  1896. 
Vol.  4,  pp.  129-175.  Reprint,  E.  L. 
Kellogg  &  Co.,  N.  Y.,  1897.    69  pp. 

Nature  Study.  Proc.  N.  E.  A.,  1896. 
pp.    156-158. 

The  Methods,  Status,  and  Prospects  of  the 


Child-study  of  To-day.  Trans.  III. 
Soc.  for  Child-study,  May,  1896,  Vol. 
2,  pp.  178-191. 

Topical  Syllabi  for  1896-97.  I.  Degrees  of 
Certainty  and  Conviction  in  Children, 
with  Maurice  H.  Small;  II.  Sabbath 
and  Worship  in  General,  with  J.  P. 
Hylan;  III.  Migrations,  Tramps, 
Truancy,  Running  Away,  etc.,  vs. 
Love  of  Home,  with  L.  W.  Kline  ;  IV. 
Adolescence,  and  its  Phenomena  in 
Body  and  Mind,  with  E.  C.  Lancaster ; 
V.  Examinations  and  Recitations,  with 
John  C.  Shaw  ;  VI.  Stillness,  Solitude, 
Restlessness,  with  H.  S.  Curtis  ;  VII. 
The  Psychology  of  Health  and  Disease, 
with  Henry  H.  Goddard  ;  VIII.  Spon- 
taneously Invented  Toys  and  Amuse- 
ments, with  T.  R.  Crosswell;  IX. 
Hymns  and  Sacred  Music,  with  Rev. 
T.  R.  Peede ;  X.  Puzzles  and  their 
Psychology,  with  Earnest  H.  Lindley  ; 
XL  The  Sermon,  with  Rev.  Alva  R. 
Scott ;  XII.  Special  Traits  as  Indices 
of  Character  and  as  Mediating  Likes 
and  Dislikes,  with  E.  W.  Bohannon ; 
XIII.  Reverie  and  Allied  Phenomena, 
with  G.  E.  Partridge  ;  XIV.  The  Psy- 
chology of  Health  and  Disease,  with  H. 
H.  Goddard. 

A  Study  of  Fears.  Am.  Jour,  of  Psy., 
Jan.,  1897,  Vol.  8,  pp.  147-249. 

Some  Practical  Results  of  Child-study. 
First  National  Congress  of  Mothers, 
Washington,  D.  C,  1897.  D.  Apple- 
ton  and  Co.,  New  York,  1897.  pp. 
165-171. 

The  Psychology  of  Tickling,  Laughing,  and 
the  Comic.  (With  Arthur  Allin.)  Am. 
Jour,  of  Psy.,  Oct.,  1897,  Vol.  9,  pp. 
1-41. 

Topical  Syllabi  for  1897-98.  I.  Immortal- 
ity, with  J.  Richard  Street ;  II.  Psy- 
chology of  Ownership  vs.  Loss,  with 
Linus  W.  Kline ;  III.  Memory,  with 
F.  W.  Colegrove  ;  IV.  Humorous  and 
Cranky  Side  in  Education,  with  L.  W. 
Kline ;  V.  The  Psychology  of  Short- 
hand Writing,  with  J.  O.  Quantz  ;  VI. 
The  Teaching  Instinct,  with  D.  E. 
Phillips  ;  VII.   Home  and  School  Pun- 


500 


Titles  of 


ishments  and  Penalties,  with  Chas. 
H.  Sears;  VIII.  Straightness  and 
Uprightness  of  Body ;  IX.  Conven- 
tionality, with  Albert  Schinz ;  X. 
Local  Voluntary  Association  among 
Teachers,  with  Henry  D.  Sheldon ; 
XI.  Motor  Education,  with  E.  W. 
Bohannon ;  XII.  Heat  and  Cold ; 
XIII.  Training  of  Teachers,  with 
W.  G.  Chambers ;  XIV.  Educational 
Ideals,  with  Lewis  Edwin  York ;  XV. 
Water  Psychoses,  with  Frederick  E. 
Bolton;  XVI.  The  Institutional  Ac- 
tivities of  Children,  with  Henry  D. 
Sheldon  ;  XVII.  Obedience  and  Obsti- 
nacy, with  Tilmon  Jenkins ;  XVIII. 
The  Sense  of  Honor  Among  Children, 
with  Robert  Clark. 

Some  Aspects  of  the  Early  Sense  of  Self. 
Am.  Jour,  of  Psy.,  April,  1898,  Vol.  9, 
pp.  351-395. 

Initiations  into  Adolescence.  Proc.  of 
Am.  Antiq.  Soc,  Worcester,  Mass., 
Oct.  21,  1898,  N.  S.  Vol.  12,  p.  367- 
400. 

The  Love  and  Study  of  Nature :  A  Part  of 
Education.  Agriculture  of  Massachu- 
setts, for  1898,  pp.  134-154. 

Topical  Syllabi  for  1898-99.  L  The  Organ- 
izations of  American  Student  Life,  with 
Henry  D.  Sheldon  ;  II.  Mathematics 
in  Common  Schools,  with  E.  B.  Bryan  ; 
III.  Mathematics  in  the  Early  Years, 
with  E.  B.  Bryan ;  IV.  Unselfishness 
in  Children,  with  Willard  S.  Small  ; 
V.  The  Fooling  Impulse  in  Man  and 
Animals,  with  Normal  Triplett ;  VI. 
Confession,  with  Erwin  W.  Runkle  ; 
VII.  Pity ;  VIII.  Perception  of 
Ehythm  by  Children,  with  Chas.  H. 
Sears. 

R6sum6  of  Child-study,  Northxoestern 
Monthly,  March-April,  1899,  Vol.  9, 
pp.  347-349.  Paidologist,  Chelten- 
ham, Eng.,  April,  1899,  Vol.  1,  pp.  5-8. 

The  Kindergarten.  School  and  Home 
Education,  Bloomington,  111.,  June, 
1899,  Vol.  18,  pp.  507-509. 

A  Study  of  Anger.  Am.  Jour,  of  Pay., 
July,  1899,  Vol.  10,  pp.  516-591. 

The  Line  of  Educational  Advance.     Out- 


look, Aug.  5,  1899,  Vol.  62,  pp.  768- 
770. 

T.   PROCTOR   HAIiL:  — 

B.A.,  University  of  Toronto,  1882  ;  Fel- 
low and  Instructor  in  Chemistry,  ibid., 
1883-84;  B.A.,  McMaster  University, 
Toronto,  1894  ;  M.A.,  and  Ph.D.,  Illi- 
nois Wesleyau  University,  1888  ;  Science 
Master,  Woodstock  College,  Wood.stock, 
Ont.,  1885-90  ;  FeUow  in  Physics, 
Clark  University,  1890-93  ;  Ph.D., 
Clark  University,  1893 ;  Professor  of 
Natural  Sciences,  Tabor  College,  Iowa, 
1893-96 ;  Professor  of  Physics,  Kansas 
City  University,  1898- ;  President  Society 
of  Economics,  Kansas  City ;  Vice-Presi- 
dent Ex-Canadian  Society,  Kansas  City. 

Author  of :  — 

The  Projection  of  Four-fold  Figures  upon 
a  Three-flat.  Am.  Jour,  of  Math., 
April,  1893,  Vol.  15,  pp.  179-189. 

The  Possibility  of  a  Realization  of  Four- 
fold Space.     Science,  May  13,  1892. 

New  Methods  of  Measuring  the  Surface 
Tension  of  Liquids.  Philosophical 
Magazine,  Nov.,  1893,  Vol.  36,  pp. 
385-413. 

Graphic  Representation  of  the  Properties 
of  the  Elements.  Proc.  Iowa  Acad, 
of  Sci.,  1894. 

A  Mad-Stone.     Ibid.,  1895. 

Physical  Theories  of  Gravitation.  Ibid., 
1895. 

Unit  Systems  and  Dimensions.  Electrical 
World,  Feb.  7,  1896. 

A  Physical  Theory  of  Electricity  and 
Magnetism.  Ibid.,  July  3,  1897,  Vol. 
30,  pp.  10-12. 

The  Vortex  Theory  of  Electricity  and 
Magnetism.  Home  Study  for  Elec- 
trical Workers,  Sept.,  1898,  pp.  34-36. 

Complex  Algebra  of  the  Plane  Extended 
to  Three-fold  Space.  Proc.  Iowa  Acad, 
of  Sci.,  1898,  Vol,  6. 

JOHN  A.    HANCOCK:  — 

B.S.,  Baker  University,  1877;  Principal 
of  Schools,  Indiana  and  Wisconsin,  1877- 
89  ;  Graduate  Student  in  Pedagogy,  Uni- 


Published  Papers. 


501 


versity  of  Wisconsin,  1889-90;  M.L., 
ibid.,  1890;  City  Superintendent,  Green 
Bay,  Wis.,  1890-92  ;  Graduate  Student 
in  Pedagogy,  Leland  Stanford  Jr.  Univer- 
sity, 1892-93;  M.A.,  ihid.,  1893;  Fellow 
in  Pedagogy,  Clark  University,  1893- 
94  ;  Superintendent  of  Schools,  Durango, 
Col. ,  1894-97  ;  Temporary  Assistant  Pro- 
fessor of  Psychology,  University  of  Colo- 
rado, 1897-98  ;  Superintendent  of  Schools, 
Santa  Barbara,  Cal.,  1899-. 

Author  of :  — 

Secularization  of  Education.     Wis.  Jour. 

of  Ed.,  March,  1890. 
Preliminary    Study    of    Motor    Ability. 

Pedagogical  Seminary,  Oct.,  1894,  Vol. 

3,  pp.  9-29. 

The  Kindergarten  and  Child  Study.  Col. 
School  Jour.,  Feb.,  1895. 

The  Relation  of  Strength  to  Flexibility  in 
the  Hands  of  Men  and  Children.  Peda- 
gogical Seminary,  Oct.,  1895,  Vol.  3, 
pp.  308-313. 

Children's  Ability  to  Reason.  Educa- 
tional Review,  Oct.,  1896,  Vol.  12,  pp. 
261-268. 

An  Early  Phase  of  the  Manual  Training 
Movement — the  Manual  Labor  School. 
Pedagogical  Seminary,  Oct.,  1897,  Vol. 
5,  pp.  287-292. 

Mental  Differences  of  School  Children. 
Proc.  N.  E.  A.,  1897,  pp.  851-857. 

Children's  Tendencies  in  the  Use  of  Writ- 
ten Language  Forms.  Northwestern 
Monthly,  June,  1898,  Vol.  8,  pp.  646- 
649. 

ROLLIN   A.  HARRIS:  — 

Ph.B.,  Cornell  University,  1885;  Fellow 
in  Mathematics,  ibid.,  1886-87  ;  Ph.D., 
ibid.,  1888 ;  Fellow  in  Mathematics, 
Clark  University,  1889-90  ;  Computer, 
United  States  Coast  and  Geodetic  Survey, 
Washington,  D.C.,  1890-. 

Author  of :  — 

The  Theory  of  Images  in  the  Representa- 
tion of  Functions.  Annals  of  Math., 
1888,  Vol.  4,  pp.  65-86,  128. 

On  the  Expansion  of    snj.     Ibid.,  Vol. 

4,  pp.  87-90. 


Design  for  a  Conicograph.  Scien.  Am. 
Supp.,  1890,  No.  740. 

On  the  Invariant  Criteria  for  the  Reality 
of  the  Roots  of  the  Quintic.  Annals 
of  Math.,  1891,  Vol.  5,  pp.  219-228. 

On  Certain  Bicircular  Quartics  Analogous 
to  Cassini's  Oval.  Mathematical  Maga- 
zine, Vol.  2,  pp.  77-79. 

Note  on  Isogonal  Transformations ;  Par- 
ticularly on  obtaining  Certain  Systems 
of  Curves  which  Occur  in  the  Statics 
of  Polynomials.  Annals  of  Math., 
1891,  Vol.  6,  pp.  77-80. 

Note  on  the  Use  of  Supplementary  Curves 
in  Isogonal  Transformation.  Am. 
Jour,  of  Math.,  1892,  Vol.  14,  pp.  291- 
300. 

Some  Connections  between  Harmonic  and 
Non-harmonic  Quantities,  Including  Ap- 
plications to  the  Reduction  and  Predic- 
tion of  Tides.  U.  S.  Coast  and  Geod. 
Sur.  Report,  1894,  Appendix,  No.  7 
(Manual  of  Tides,  Part  III.). 

Introduction  and  Historical  Treatment  of 
the  Subject,  Ibid.,  1897,  Appendix, 
No.  8  (Manual  of  Tides,  Part  I.). 

Tidal  Observation,  Equilibrium  Theory, 
and  the  Harmonic  Analysis,  Ibid., 
1897,  Appendix,  No.  9  (Manual  of 
Tides,  Part  II.). 

A  Proposed  Tidal  Analyzer.  Physical 
Review,  1899,  Vol.  8,  pp.  54-60. 

JAMES  N.    HART:  — 

B.C.E.,  Maine  State  College,  1885  ;  Prin- 
cipal of  High  School,  Dennysville,  Me., 
1885 ;  Instructor  in  Mathematics  and 
Drawing,  Maine  State  College,  1887-90 ; 
C.E.,  ibid.,  1890  ;  Scholar  in  Mathe- 
matics, Clark  University,  1890-91 ; 
Professor  of  Mathematics  and  Astronomy, 
University  of  Maine,  1891-;  Graduate  Stu- 
dent in  Mathematics  and  Astronomy,  Uni- 
versity of  Chicago,  1894-95;  M.S.,  ibid., 
1897  ;  Member  of  American  Mathematical 
Society. 

S.  B.  HASLETT:  — 

Graduate,  Edinboro,  Pa.,  State  Normal 
School,  1885  ;  Principal,  Creighton  Pub- 
lic  Schools,  1887-88;    A.B.,  Grove   City 


502 


Titles  of 


College,  Pa.,  1889;  Principal,  Braddock 
High  School,  1891-92  ;  Graduate,  Alle- 
gheny Theological  Seminary,  1892  ;  Pres- 
byterian Ministry,  1892-;  A.M.,  Grove 
City  College,  1896 ;  Scholar  in  Psy- 
chology, Clark  University,  1898-99. 

N.  B.  HELLER:  — 

B.S.,  University  of  Pennsylvania,  1884; 
Professor  of  Mathematics,  Boys'  High 
School,  Reading,  Pa.,  1887-91;  Scholar 
in  Mathematics,  Clark  University, 
1891-92  ;  Fellow  in  Mathematics,  Uni- 
versity of  Chicago,  1892-93 ;  Assistant 
Professor  in  ]\Iathematics,  Drexel  Insti- 
tute, Philadelphia,  1893-. 

CLARK  •WILSON  HETHERINGTON  : 
A.B.,  Leland  Stanford  Jr.  University, 
1895 ;  Instructor,  Encina  Gymnasium, 
Stanford  University,  1893-96  ;  Statistician 
and  Director  of  Physical  Training,  Whit- 
tier  State  Reform  School,  1896-98  ;  Fel- 
low in  Psychology,  Clark  University, 
1898-99. 

JOHN  E.  HILL  :  — 

Ph.B.,  Sheffield  Scientific  School  (Yale), 
1885  ;  Resident  Engineer,  C.  M.  and  St. 
Paul  R.R.,  1885-88;  Professor  of  Mathe- 
matics, Military  Academy,  Louisville, 
Ky.,  1888-89  ;  Superintendent  of  Schools, 
Pleasantville,  N,  Y.,  1889-90;  Professor 
of  Mathematics  and  Civil  Engineering, 
Highland  Park  College,  1890-92  ;  Fellow 
in  Mathematics,  Clark  University, 
1892-95  ;  Ph.D.,  Clark  University, 
1895;  Tutor  in  Mathematics,  Columbia 
University,  1895-97  ;  Teacher  of  Mathe- 
matics, Manual  Training  High  School, 
Brooklyn,  N.  Y.,  1897-98  ;  Teacher  of 
Science,  High  School,  Stamford,  Ct., 
1898-99. 

Author  of :  — 

On  Quintic  Surfaces.    Mathematical  Be- 

vieiv,  July,  1896,  Vol.  1,  pp.  1-59. 
Bibliography   of    Surfaces    and    Twisted 

Curves.     Btill.  A771.  Math.  Soc,  Jan., 

1897,  Vol.  3,  pp.  133-146. 
On  Three  Septic  Surfaces.    Am.  Jour,  of 

Math.,  Oct.,  1897,  Vol.  19,  pp.  289-311. 


BENJAMIN  C.  HINDE  :  — 

A.B.,  Central  College,  Missouri,  1881  ; 
A.M.,  ibid.,  1882;  Instructor  in  Physical 
Sciences,  Howard  College,  1882-88  ;  Grad- 
uate Student,  Johns  Hopkins  University, 
1888-90  ;  Professor  of  Physics  and  Chem- 
istry, State  Normal  College,  Mo.,  1890-91  ; 
Professor  of  Physics,  Trinity  College,  N. 
C,  1891-92;  Fellow  and  Assistant  in 
Physics,  Clark  University,  1892-93 ; 
Professor  of  Physics,  Trinity  College, 
N.  C,  1893-94. 
Died  Feb.  6,  1894. 

CLIFTON   F.    HODGE:  — 

A.B.,  Ripon  College,  1882;  Civil  En- 
gineer, Montana,  1882-86  ;  Graduate  Stu- 
dent, Johns  Hopkins  University,  1886-88  ; 
Fellow  in  Biology,  ibid,  1888-89  ;  Ph.D., 
Johns  Hopkins  University,  1889  ;  Fellow 
in  Psychology  and  Assistant  in  Neu- 
rology, Clark  University,  1889-91 ; 
Instructor  in  Biologj%  University  of  Wis- 
consin, 1891-92  ;  Assistant  Professor 
of  Physiology  and  Neurology,  Clark 
University,  1892- ;  Member  of  :  Ameri- 
can Physiological  Society,  Society  Ameri- 
can Naturalists,  Massachusetts  Forestry 
Association,  Boston  Society  of  Medical 
Sciences. 

Author  of :  — 

Some  Effects  of  Stimulating  Ganglion 
Cells.  Am.  Joxir.  of  Psy.,  May,  1888, 
Vol.  1,  pp.  479-486. 

Some  Effects  of  Electrically  Stimulating 
Ganglion  Cells.  Ibid.,  May,  1889, Vol. 
2,  pp.  376-402. 

A  Study  of  the  Oyster  Beds  of  Long 
Island  Sound  with  Reference  to  the 
Ravages  of  Starfish.  J.  H.  U.  Circular, 
Sept.,  1889,  No.  75,  Vol.  8,  p.  102. 

A  Sketch  of  the  History  of  Reflex  Action. 
Am.  Jour,  of  Psy.,  April  and  Sept., 
1890,  Vol.  3,  pp.  149-167,  343-363. 

The  Process  of  Recovery  from  the  Fatigue 
occasioned  by  the  Electrical  Stimula- 
tion of  Cells  of  the  Spinal  Ganglia. 
Ibid.,  Feb.,  1891,  Vol.  3,  pp.  530- 
543. 

Homing  Pigeons,     .^gis,  Jime,  1892. 


Published  Papers. 


503 


A  Microscopical  Study  of  Changes  due  to 
Functional  Activity  in  Nerve  Cells. 
Jour,  of  3Iorph.,  Nov.,  1892,  Vol.  7, 
pp.  95-168. 

The  Method  of  Homing  Pigeons.  Pop. 
Sci.  Mo.,  April,  1894,  Vol.  44,  pp. 
758-775. 

Changes  in  Ganglion  Cells  from  Birth  to 
Senile  Death.  Observations  on  Man 
and  Honeybee.  Jour,  of  Fhys.,  1894, 
Vol.  17,  pp.  129-134. 

Botanical  Gardens.  Wor.  Co.  Hort.  8oc. 
Sep.,  1894-95,  pp.  102-117. 

Die  Nervenzelle  bei  der  Geburt  und  beim 
Tode  an  Alterschwache.  Anat.  An- 
zeiger,  Aug.  1,  1894,  Vol.  9,  pp.  706- 
710. 

A  Microscopical  Study  of  the  Nerve  Cell 
during  Electrical  Stimulation.  Jour, 
of  Morph.,  Sept.,  1894,  Vol.  9,  pp. 
449-463. 

The  Daily  Life  of  a  Protozoan :  A  Study 
in  Comparative  Psycho-Physiology. 
(With  H.  A.  Aikins.)  Am.  Jour,  of 
Psy.,  Jan.,  1895,  Vol.  6,  pp.  524-533. 

The  Vivisection  Question.  Pop.  Sci.  Mo., 
Sept.  and  Oct.,  1896,  Vol.  49,  pp.  614- 
624,  771-785. 

Experiments  on  the  Physiology  of  Alcohol, 
made  under  the  Auspices  of  the  Com- 
mittee of  Fifty.  Ibid.,  March  and 
April,  1897,  Vol.  50,  pp.  594-603, 
796-812. 

Horticultural  Interests  in  Kelation  to 
Public  Education.  Wor.  Co.  Hort. 
Soc.  Pep.,  1898,  pp.  62-81. 

The  Common  Toad.  Nature  Study  Leaf- 
let. Biology  Series,  No.  1,  1898. 
Worcester,  Mass.  15  pp. 

Our  Common  Birds.  Biology  Series,  No. 
2,  1899.     Worcester,  Mass.  34  pp. 

FREDERICK   H.    HODGE:  — 

A.B.,  Boston  University,  1894;  A.M., 
ibid.,  1899 ;  Special  Student,  Bridgewater 
Normal  School,  1894-95;  Professor  of 
Mathematics,  J.  B.  Stetson  University, 
1895-96 ;  Graduate  Student  in  Mathe- 
matics, University  of  Chicago,  1896-97  ; 
Scholar  in  Mathematics,  Clark  Uni- 
versity,   1897-98  ;  Fellow,   1898-99  ; 


Professor  of  Mathematics  and  History, 
Bethel  College,  Russellville,  Ky.,  1899-. 

THOMAS  FRANKLIN  HOLGATE  : — 
B.A.,  Victoria  University,  Toronto,  1884  ; 
Mathematical  Master,  Albert  College, 
Belleville,  Ont.,  1884-90;  M.A.,  Victoria 
University,  1889 ;  Fellow  in  Mathe- 
matics, Clark  University,  1890-93  ; 
Ph.D.,  Clark  University,  1893;  In- 
structor in  Mathematics,  Northwestern 
University,  1893-94 ;  Professor  of  Ap- 
plied Mathematics,  ibid.,  1894- ;  Member 
of  the  American  Mathematical  Society. 

Author  of :  — 

On  the  Cone  of  the  Second  Order  which 
is  Analogous  to  the  Nine  Point  Conic. 
Aiinals  of  Math.,  1893,  Vol.  7,  pp. 
73-76. 

On  Certain  Ruled  Surfaces  of  the  Fourth 
Order.  Am.  Jour,  of  Math.,  Oct., 
1893,  Vol.  15,  pp.  344-386.  Addi- 
tional Note  on  same.  Ibid.  (In 
press.) 

Correction  of  an  Error  in  Salmon's  "  Ge- 
ometry of  Three  Dimensions."  Bull. 
N.  Y.  Math.  Soc,  1894,  Vol.  3,  p.  224. 

A  Geometrical  Locus  connected  with  a 
System  of  Coaxial  Circles.  Bull.  Am. 
Math.  Soc,  Nov.,  1897,  2d  ser.,  Vol. 
4,  pp.  63-67. 

A  Second  Locus  connected  with  a  System 
of  Coaxial  Circles.  Ibid.,  Dec,  1898, 
Vol.  5,  pp.  135-143. 

Reye's  "Lectures  on  the  Geometry  of 
Position ' '  (translation) ,  Part  I.  Mac- 
millan  Company,  New  York,  1898. 
248  pp. 

RICHARD   J.   HOLLAND:  — 

B.A.,  Victoria  College,  Toronto,  1887 ; 
Certificate  Specialist  in  Science,  Teachers' 
Training  Institute,  Kingston,  Ont.,  1887- 
88  ;  Science  Master,  Morrisburg  Collegiate 
Institute,  1888-90  ;  Graduate  Student,  Uni- 
versity of  Leipzig,  1890-93  ;  Ph.D.,  Uni- 
versity of  Leipzig,  1893  ;  Honorary 
Fellow  in  Physics,  Clark  University, 
1893-94 ;  with  Westinghouse  Electric 
Company,  Pittsburg,  Pa.,  1894-95;  with 


J 


504 


Titles  of 


Electric  Power  Storage  Company,  N.  Y. 
City,  April,  1895-. 

Author  of :  — 

Ueber  die  Aenderung  der  electrlschen 
Leitfahigkeit  einer  Losung  durch  Zu- 
satz  von  kleinen  Mengen  eines  Nicht- 
leiters.  Wied.  Annalen,  Sept.,  1893, 
Vol.  50,  pp.  261-292. 

Ueber  die  electrische  Leitfahigkeit  von 
Kupferchloridlosungen.  Ibid.,  pp.  349- 
360. 

R.  C.  HOLLENBAUGH  :  — 

A.B.,  Bucknell  University,  1888;  Princi- 
pal, Cross  Creek  Academy,  1888-89 ; 
A.M.,  Bucknell  University,  1891;  Ph.D., 
Wooster  University,  1891  ;  Graduate  Stu- 
dent, Johns  Hopkins  University,  1891-92  ; 
Scholar  in  Psychology,  Clark  Univer- 
sity, 1892. 
Died  July  6,  1893. 

T^ILLIAM   A.   HOYT:  — 

A.B.,  Bates  College,  1880;  Principal 
High  School,  Rockport,  Me.,  1881-82; 
Principal  Greeley  Institute,  Cumberland, 
Me.,  1882-83  ;  Cornwall  Heights  School, 
Cornwall,  N.  Y.,  1883-86;  A.M.,  Bates 
College,  1884;  Principal  High  School :  Med- 
way,  Mass.,  1886-88,  North  Brookfield, 
Mass.,  1888-92,  Augusta,  Me.,  1892-93; 
Scholar  in  Pedagogy,  Clark  Universi- 
ty, 1893-94  ;  Superintendent  of  Schools, 
Brookfield,  Mass.  (District),  1894-. 

Author  of :  — 

The  Love  of  Nature  as  the  Root  of  Teach- 
ing and  Learning  the  Sciences.  Peda- 
gogical Seminary,  Oct.,  1894,  Vol.  8, 
pp.  61-86. 

EDMUND   B.  HUEY:  — 

A.B.,  Lafayette  College  (First  Honors 
in  Philosophy  and  Anglo-Saxon),  1895;  In- 
structor in  Latin,  Harry  Hillman  Academy, 
Wilkesbarre,  Pa.,  1896-97;  Scholar  in 
Psychology,  Clark  University,  1897- 
98  ;  Fellow,  1898-99;  Professor  of  Psy- 
chology, State  Normal  School,  Moor- 
head,  Minn.,  1899-. 


Author  of:  — 

Preliminary  Experiments  in  the  Physi- 
ology and  Psychology  of  Reading. 
Am.  Jour,  of  Psy.,  July,  1898,  Vol.  9, 
pp.  575-686. 

D.  D.  HUGH  :  — 

A.B.,  Dalhousie  College,  1891;  A.B., 
Harvard  University,  1892  ;  A.M.,  Cornell 
University,  1893  ;  Fellow  in  Psychol- 
ogy, Clark  University,  1895-96  ;  Prin- 
cipal of  High  School,  La  Junta,  Col., 
1896-98;  Professor  of  Psychology,  Colo- 
rado State  Normal  School,  Greeley,  Col., 
1898-99  ;  Professor  of  Pedagogy  and  Eng- 
lish, State  Agricultural  College,  Logan, 
Utah,  1899-. 
Author  of :  — 

Formal  Education  fiom  the  Standpoint  of 
Physiological  Psychology.  Pedagogi- 
cal Seminary,  April,  1898,  Vol.  5, 
pp.  599-605. 
The  Animism  of  Children.  Northwestern 
Monthly,  June,  1899,  Vol.  9,  pp.  450- 
453. 

LORRAIN   S.  HULBURT:  — 

A.B.,  University  of  Wisconsin,  1883  ;  A.M., 
ibid.,  1888;  Professor  of  Mathematics, 
University  of  So.  Dakota,  1887-91  ;  Grad- 
uate Student,  University  of  Gottingen, 
1889-90  ;  Fellow  in  Mathematics,  Clark 
University,  1891-92 ;  Instructor  in 
Mathematics,  Johns  Hopkins  University, 
1892-94  ;  Ph.D.,  Johns  Hopkins  Univer- 
sity, 1894  ;  Associate  in  Mathematics, 
ibid.,  1894-97 ;  Collegiate  Professor  of 
Mathematics,  ibid. ,  1897- ;  Member  of 
American  Mathematical  Society. 
Author  of :  — 

Theorems  on  the  Number  and  Arrange- 
ment of  the  Real  Branches  of  Plane 
Algebraic  Curves.  Am.  Jour,  of  Math., 
July,  1892,  Vol.  14,  pp.  246-250. 
Topology  of  Algebraic  Curves.  Bull,  of 
the  N.  Y.  Math.  Soc,  1892,  Vol.  1, 
pp.  197-202. 

JOHN  I.  HUTCHINSON :  — 

A.B.,  Bates  College,  1889;    Scholar  in 
Mathematics,  Clark  University,  1890- 


Puhlished  Papers. 


605 


91 ;  Fellow,  1891-92  ;  Fellow  in  Mathe- 
matics, University  of  Chicago,  1892-94  ; 
Instructor  in  Mathematics,  Cornell  Uni- 
versity, 1894- ;  Ph.D.,  University  of 
Chicago,  1896 ;  Member  of  American 
Mathematical  Society. 

Author  of :  — 

A  Special  Form  of  a  Quartic  Surface, 
An7ials  of  Math.,  June,  1897,  Vol.  2, 
pp.  158-160. 

On  the  Reduction  of  Hyperelliptic  Func- 
tions, (p  =  2)  to  Elliptic  Functions  by  a 
Transformation  of  the  Second  Degree. 
(Dissertation.)  Gottingen,  1897.    40  pp. 

Note  on  the  Tetrahedroid.  Bull,  of  the 
Am.  Math.  Soc,  April,  1898,  2d  ser.. 
Vol.  4,  pp.  327-329. 

The  Hessian  of  the  Cubic  Surface.  Ibid. , 
March,  1899,  2d  ser..  Vol.  5,  pp.  282- 
292. 

The  Asymptotic  Lines  of  the  Kummer 
Surface.  Ibid.,  July,  1899,  2d  ser.. 
Vol.  5,  pp.  465-467. 

JOHN  P.   HYLAN  :  — 

Student,  Harvard  University,  1891-95 ; 
Fellow  in  Psychology,  Clark  Univer- 
sity, 1895-97 ;  Instructor  in  Psychology, 
University  of  Illinois,  1897-98 ;  Assistant 
Professor,  ibid.,  1898-99 ;  Member  of 
Executive  Commission  of  Illinois  Society 
of  Child  Study. 

Author  of :  — 

Fluctuation  of  Attention.  (Studies  from 
the  Harvard  Psy.  Lab.)  Psychological 
Eeview,  Jan.,  1896,  Vol.  3,  pp.  56-63. 

The  Fluctuation  of  Attention.  Psycho- 
logical Beview,  Monograph  Supple- 
ment, March,  1898,  Vol.  2,  No.  2. 
78  pp. 

MASSUO  IKUTA:  — 

Student,  University  of  Tokio,  Japan,  1880- 
85  ;  University  of  Berlin,  1886  ;  University 
of  Erlangen,  1887-88;  Ph.D.,  University 
of  Erlangen,  1888  ;  Consulting  Chemist, 
Tokio,  Japan,  1889-90 ;  Assistant  in 
Chemistry,  Clark  University,  1890- 
92  ;  Assistant  in  Chemistry,  University  of 
Chicago,  1892-95 ;  Instructor,  ibid.,  1895-. 


Author  of :  — 

Ueber  die  Einwirkung  von  Acetessigather 
auf  Chinone  ;  Synthese  von  Benzofur- 
furan-Derivaten.  Jour,  fur  praktische 
Chemie,  1892,  Vol.  45,  pp.  65-83, 

Metamidophenol  and  its  Derivatives,  Am. 
Chem.  Jour.,  Jan.,  1893,  Vol.  15,  pp. 
39-44. 

JAMES  EDMUND  IVES :  — 

Jessup  Student,  Academy  of  Natural 
Sciences,  1887-91 ;  Assistant  Curator, 
ibid.,  1887-93;  Instructor  in  Physics, 
Drexel  Institute,  1893-97 ;  Student  in 
Histology  and  Embryology,  University  of 
Pennsylvania,  1888-89  ;  Student  in  Mathe- 
matics, ibid.,  1893-95  ;  Student  in  Physics, 
Cavendish  Laboratory,  Cambridge,  Eng., 
1896 ;  Scholar  in  Physics,  Clark  Uni- 
versity, 1897-98 ;  Fellow,  1898-99. 

Author  of :  — 

On  Two  New  Species  of  Starfishes.    Proc. 

Acad.  Nat.  Sci.  of  Phila.,  1888,  pp. 

421-424. 
Linguatula    Diesingii,    from    the    Sooty 

Mangabey.     Ibid.,    1889,   p.  31. 
Variation    in    Ophiura   Panamensis    and 

Ophiura  teres.     Ibid.,  1889,   pp.    76- 

77. 
On  a  New  Genus  and  Two  New  Species  of 

Ophiurans.    Ibid.,  1889,  pp.  143-145. 
Catalogue  of  the  Asteroidea  and  Ophiuroi- 

dea  in  the  Collection  of  the  Academy 

of  Natural  Sciences  of  Philadelphia. 

Ibid.,  1889,  pp.  169-179. 
Mimicry  of  the  Environment  in  Ptero- 

phryne  histrio.     Ibid.,  1889,  pp.  344- 

345. 
On    Arenicola    cristata    and    Its    Allies. 

Ibid.,  1890,  pp.  73-75. 
Echinoderms  from  the  Northern  Coast  of 

Yucatan  and  the  Harbor  of  Vera  Cruz. 

Ibid.,  1890,  pp.  317-340. 
Crustacea  from  the    Northern    Coast  of 

Yucatan,  the   Harbor  of  Vera  Cruz, 

the   West   Coast  of  Florida  and  the 

Bermuda   Islands.      Ibid.,    1891,    pp. 

176-207. 
Echinoderms  and  Arthropods  from  Japan. 

Ibid.,  1891,  pp.  210-223. 


606 


Titles  of 


Echiuoderms  from  the  Bahama  Islands. 
Ibid.,  1891,  pp.  337-341. 

Reptiles  and  Batrachians  from  Northern 
Yucatan  and  Mexico.  Ibid.,  1891,  pp. 
458-463. 

Echinoderms  and  Crustaceans  collected  by 
the  West  Greenland  Expedition  of  1891. 
Ibid.,  1891,  pp.  479-481. 

A  New  Species  of  Pycnogonum  from  Cali- 
fornia.    Ibid.,  1892,  pp.  142-144. 

TILMON  JENKINS :  — 

B.A.,  National  Normal  University,  1882  ; 
Professor  of  Didactics,  Salina,  Kan., 
Normal  University,  1883-85 ;  Superin- 
tendent of  Schools,  Kingman,  Kan.,  1885- 
87  ;  M.  A. ,  National  Normal  University, 
1891 ;  Educational  work  in  Colorado, 
1887-96 ;  Assistant  State  Superintendent 
of  Public  Instruction,  Colorado,  1894 ; 
Superintendent  of  Schools,  Santa  F^,  New 
Mexico,  1896-97  ;  Scholar  in  Pedagogy, 
Clark  University,  1897-98 ;  Special 
Student,  University  of  Colorado,  1898-99. 

GEORGE  ELLSWORTH  JOHNSON:  — 
A.B.,  Dartmouth  College,  1887 ;  A.M., 
ibid.  1891  ;  Principal,  Colebrook  Acad- 
emy, N.  H.,  1887-88  ;  Principal  of  Schools, 
Springfield,  Vt.,  1888-92  ;  Student,  Hart- 
ford Theological  Seminaiy,  1892-93; 
Scholar  in  Pedagogy,  Clark  Univer- 
sity, 1893-94  ;  Fellow,  1894-95  ;  Su- 
perintendent of  Schools,  Andover,  Mass., 
1895-. 

Author  of :  — 

Education  by  Plays  and  Games.  Peda- 
gogical Seminary,  Oct.,  1894,  Vol.  3, 
pp.  97-133. 

Contribution  to  the  Psychology  and  Peda- 
gogy of  Feeble-minded  Children.  Ibid., 
Oct.,  1895,  Vol.  3,  pp.  246-301. 

Play  in  Education.  Northwestern  Monthly, 
July,  1897,  Vol.  8,  pp.  3-8. 

Games  and  Play.  First  of  Series  of 
Twelve  Monographs  on  Social  Work. 
Issued  by  Lincoln  House,  Boston, 
Mass.,  and  The  Commons,  Chicago, 
111.  The  Co-operative  Press,  Cam- 
bridge, 1898.     22  pp. 


Play  in  Physical  Education.  Am.  Phys. 
Ed.  Rev.,  Sept.,  1898,  Vol.  3,  pp.  179- 
187. 

The  New  Education.  Address  delivered 
before  the  Andover  Burns  Club, 
March  19,  1898.  The  Andover  Press, 
Andover,  Mass.,  1898.     15  pp. 

HERBERT  P.  JOHNSON  :  — 

A.B.,  Harvard  University  (with  Honors 
in  Natural  History),  1889;  A.M.,  ibid., 
1890  ;  Assistant  in  Biology,  Williams  Col- 
lege, 1890-91  ;  Fellow  in  Morphology, 
Clark  University,  1891-92  ;  Fellow  in 
Morphology,  University  of  Chicago,  1892- 
94  ;  Ph.D.,  University  of  Chicago,  1894  ; 
Instructor  in  Biology,  Des  Moines  Col- 
lege, 1894 ;  Assistant  Professor  of  Zo- 
ology, University  of  California,  1894- ; 
Member  of :  American  Society  of  Natu- 
ralists ;  California  Academy  of  Sciences ; 
San  Francisco  Microscopical  Society. 

Author  of :  — 

Amitosis  in  the  Embryonal  Envelopes  of 
the  Scorpion.  Bull.  3Iuseum  Com- 
parative Zool.,  Harvard  College,  1892, 
Vol.  22,  pp.  127-161  ;  3  pis. 

A  Contribution  to  the  Morphology  and 
Biology  of  the  Stentors.  Jour,  of 
Morph.,  Aug.,  1893,  Vol.  8,  pp.  468- 
562  ;  4  pis. 

The  Plastogamy  of  Actinosphserium. 
Ibid.  April,  1894,  Vol.  9,  pp.  269-276. 

A  Preliminary  Account  of  the  Marine 
Annelids  of  the  Pacific  Coast,  with 
Descriptions  of  New  Species.  Proc. 
California  Academy  of  Sciences,  Third 
Series.  Zoology,  1897,  Vol.  1,  pp. 
153-198  ;  6  pis. 

EDWIN   O.    JORDAN:  — 

S.B.,  Massachusetts  Institute  of  Tech- 
nology, 1888  ;  Chief  Assistant  Biologist, 
Massachusetts  State  Board  of  Health, 
1888-90  ;  Lecturer  in  Biology,  Massachu- 
setts Institute  of  Technology,  1889-90  ; 
Fellow^  in  Morphology,  Clark  Uni- 
versity, 1890-92;  Ph.D.,  Clark  Uni- 
versity, 1892 ;  Associate  in  Biology, 
University  of  Chicago,  1892-93 ;  Instructor 


Published  Papers. 


507 


in  Biology,  ihid.^  1893-95  ;  Assistant  Pro- 
fessor of  Bacteriology,  ibid.,  1895-. 

Author  of :  — 

Phagocytosis    and    Immunity,      Boston 
Med.  and  Surg.  Jour.,  1890,  Vol.  122, 
p.  406. 
Eecent  Theories  on  the  Function  of  the 
White  Blood-Cell.     Technology  Quar- 
terly, 1890,  Vol.  3,  p.  170. 
Certain  Species  of  Bacteria  observed  in 
Sewage.     Beport  of  the  Mass.    State 
Board  of  Health  on  Water  Supply  and 
Sewage,  1889-90,  Vol.  2,  p.  821. 
Investigations    on    Nitrification    and  the 
Nitrifying  Organisms.  (With  Mrs.  Ellen 
H.  Richards.)    Ibid.,  Vol.  2.    Volume 
on  Water  Supply  and  Sewage,  1890, 
p.  865. 
The     Spermatophores    of     Diemyctylus. 
Jour,  of  Morph.,  Sept.,  1891,  Vol.  5, 
pp.  263-270. 
The  Cleavage  of  the  Amphibian  Ovum. 
(With  A.   C.   Eycleshymer. )      Anat. 
Anzeiger,    Sept.     15,    1892,    Vol.    7, 
pp. 622-624. 
The  Habits  and  Development  of  the  Newt. 
Jour,  of  Morph.,  May,  1893,  Vol.  8, 
pp.  270-366,  5  Plates. 
On  the  Cleavage  of  Amphibian  Ova.    (With 
A.    C.    Eycleshymer.)      Ibid.,    Sept., 
1894,  Vol.  9,  pp.  407-416,  1  Plate. 
The  Identification  of  the  Typhoid  Fever 
Bacillus.      Jour.    Am.    Med.    Ass''n, 
Dec.  22,  1894. 
On    Some   Conditions   affecting  the   Be- 
havior   of    the    Typhoid    Bacillus    in 
Water.     Medical  News,  Sept.  28, 1895. 
The  "Inheritance"  of  Certain  Bacterial 
Diseases.      Chicago    Med.    Becorder, 
Aug.,  1898,  Vol.  15,  p.  82. 
The  Production  of  Fluorescent  Pigment  by 
Bacteria.      Botanical    Gazette,    Jan., 
1899,  Vol.  27,  p.  19. 
Translation  of  the  Principles  of  Bacteri- 
ology by  Professor  F.  Hueppe.    Open 
Court  Publishing  Co.,  Chicago.    467  pp. 
The  Death-rate  from  Diphtheria  in  the 
Large   Cities    of    the    United    States. 
Philadelphia    Med.    Jour.,    Feb.    18, 
1899. 


F.    C.    KENYON:  — 

B.Sc,  University  of  Nebraska,  1892  ;  In- 
structor in  Zoology,  ibid.,  1891-93  ;  Assist- 
ant and  Fellow  in  Biology,  Tufts  College, 
1893-95  ;  A.M.  and  Ph.D.,  Tufts  College, 
1895  ;  Fellow  in  Biology,  Clark  Uni- 
versity, 1895-96  ;  Fellow,  American 
Association  for  the  Advancement  of 
Science  ;  Member  of  :  American  Morpho- 
logical Society,  American  Society  of 
Naturalists,  National  Geographic  Society. 

Author  of  :  — 

The  Morphology  and  Classification  of  the 
Pauropoda.  Tufts  College  Studies, 
1895. 

In  the  Region  of  the  New  Fossil ;  Dse- 
mouelix.     American  Naturalist,  1895. 

Formal  as  a  Preserving  Agent.  Ibid., 
1895. 

The  Meaning  and  Structure  of  the  So- 
called  Mushroom  Bodies  of  the  Hexa- 
pod  Brain.     Ibid.,  1896. 

The  Brain  of  the  Bee.  Jour.  Comp.  Neu- 
rology, 1896. 

The  Optic  Lobe  of  the  Bee's  Brain  in  the 
Light  of  Recent  Neurological  Methods. 
1897. 

Delarvation.     American  Naturalist,  1897. 

The  Chartognaths  of  American  Waters. 
Ibid. 

The  Regeneration  of  an  Antenna-like 
Structure  instead  of  an  Eye.     Ibid. 

The  Regeneration  of  the  Lens  of  the  Eye 
of  Tritan.     Ibid. 

Formol  or  Formalin.     Ibid. 

Effect  of  Lithium  Chloride  upon  the  De- 
velopment of  the  Frog  and  Toad  Egg. 
Ibid.,  1896. 

The  Terminology  of  the  Neurocytes, 
Science,  1897. 

HERBERT   G.    KEPPEL:  — 

A.B.,  Hope  College,  Holland,  Mich., 
1889  ;  Instructor  in  Mathematics,  North- 
western Classical  Academy,  Orange  City, 
la.,  1891-92;  Scholar  in  Mathematics, 
Clark  University,  1892-93;  Fellow, 
1893-95  ;  Instructor  in  Mathematics, 
Academy  of  Northwestern  University, 
Evanston,    111.,    1895-96;    Instructor   in 


508 


Titles  of 


Mathematics,  Northwestern  University, 
Evanston,  111.,  1896- ;  Member  of  the 
American  Mathematical  Society  ;  Member 
of  Het  Wiskundig  Genootschap,  Amster- 
dam. 

E.    A.    KIRKPATRICK : — 

B.Sc,  Iowa  Agricultural  College,  1887; 
M.Ph.,  lUd.,  1889;  Scholar  in  Psy- 
chology, Clark  University,  1889-90  ; 
Fellow,  1890-91 ;  Professor  of  Psy- 
chology and  Pedagogy,  State  Normal 
School,  Winona,  Minn.,  1892-97 ;  Pro- 
fessor of  Psychology  and  Child  Study, 
State  Normal  School,  Fitchburg,  Mass., 
1898- ;  Member  of  American  Psychologi- 
cal Association. 

Author  of :  — 

Observations  on  College  Seniors  and  Elec- 
tives  in  Psychological  Subjects.  Am. 
Jour,  of  Psy.,  April,  1890,  Vol.  3,  pp. 
168-173. 

Number  of  Words  in  an  Ordinary  Vocabu- 
lary. Science,  Aug,  21,  1891,  Vol.  18, 
pp.  107-108. 

How  Children  learn  to  Talk.  Ibid., 
Sept.  25,  1891,  Vol.  18,  pp.  175-176. 

Mental  Images.  Ibid. ,  Oct.  27,  1893,  Vol, 
22,  pp.  227-230. 

An  Experimental  Study  of  Memory.  Psy- 
chological Eeview,  Nov.,  1894,  Vol.  1, 
pp.  602-609. 

Inductive  Psychology:  An  Introduction 
to  the  Study  of  Mental  Phenomena. 
E.  L.  Kellogg  &  Co.,  New  York,  1895. 
208  pp. 

Child  Study  in  the  Training  of  Teachers. 
Review  of  Bevieios,  Dec,  1896,  Vol. 
14,  pp.  686-692. 

Handbook  of  Minnesota  Child-Study  As- 
sociation. James  and  Kroeger,  Wi- 
nona, Minn.,  1897.     60  pp. 

Continuous  Sessions  of  Schools.  Review 
of  Reviews,  July,  1897,  Vol.  16,  pp. 
190-191. 

Play  as  a  Factor  in  Social  and  Educa- 
tional Reforms.  Ibid.,  Aug.,  1899, 
Vol.  20,  pp.  192-196. 

Children's  Reading.  Northwestern  Month- 
ly, June,  1898,  Vol.  8.  pp.  651-654; 


Dec,  1898,  Jan.,  March-April,  1899, 
Vol.  9,  pp.  188-191,  229-2.33,  338-342. 

Learning  Voluntary  Movements.  School 
and  Home  Education,  March,  1899, 
Vol.  18,  pp.  337-344. 

The  Development  of  Voluntary  Move- 
ment. Psychological  Review,  May, 
1899,  Vol.  6,  pp.  275-281. 

MILTON    S.  KISTLER:  — 

Graduate,  West  Chester,  Pa.,  State  Nor- 
mal School,  1888  ;  Principal,  High  School, 
Honey  Brook,  Pa.,  1888-89;  Principal, 
Blaine  Normal  Institute,  Pa.,  1889-90 ; 
Ph.B.,  Dickinson  College,  1894;  A.M., 
ibid.,  1897  ;  Professor  of  Latin  and  Eng- 
lish, Edinboro,  Pa.,  State  Normal  School, 
1894-97  ;  Scholar  in  Pedagogy,  Clark 
University,  1897-98 ;  Teacher,  N.  Y. 
City  Schools,  1898-. 

Author  of  :  — 

John  Knox's  Services  to  Education.  Edu- 
cation, Boston,  Mass.,  Oct.  1898,  Vol. 
19,  pp.  105-116. 

LINUS   "W.  KLINE:  — 

Student,  University  of  Virginia,  1886-87  ; 
L.I.,  Peabody  Normal  College,  1889; 
Principal,  Hamilton  Grammar  School, 
Houston,  Texas,  1891-93  ;  B.S.,  Harvard 
University,  1896 ;  Scholar  in  Psychol- 
ogy, Clark  University,  1896-97  ;  Fel- 
low, 1897-98 ;  Ph.D.,  Clark  Univer- 
sity, 1898  ;  Honorary  Fellow  and 
Assistant  in  Psychology,  1898-99 ; 
Professor  of  Psychology  and  Pedagogy, 
State  Normal  School,  Mankato,  Minn., 
1899-. 

Author  of :  — 

Truancy  as  Related  to  the  Migrating  In- 
stinct. Pedagogical  Seminary,  Jan., 
1898,  Vol.  5,  pp.  381-420. 

The  Migratory  Impulse  vs.  Love  of  Home. 
Am.  Jour,  of  Psy.,  Oct.  1898,  Vol.  10, 
pp.  1-81. 

Methods  in  Animal  Psychology.  Ibid., 
Jan.,  1899,  Vol.  10,  pp.  2-56-279. 

Suggestions  toward  a  Laboratory  Course 
in  Comparative  Psychology.  Ibid., 
April,  1899,  Vol.  10,  pp.  399-430. 


Published  Pajyers. 


509 


The  Psychology  of  Ownership.  (With  C. 
J.  France.)  Pedagogical  Seminary. 
(In  press.) 

"WILLIAM  O.  KROHN:  — 

A.B. ,  Western  College,  1887 ;  Ph.D., 
Yale  University,  1889 ;  Instructor  in  Phi- 
losophy and  Psychology,  Western  Eeserve 
University,  1889-91  ;  Inspecting  Psycho- 
logical Laboratories  in  German  Universi- 
ties, July,  1891-Feb.  1892  ;  Fellow  in 
Psychology,  Clark  University,  March- 
June,  1892 ;  Professor  of  Psychology, 
University  of  Illinois,  1892-97  ;  Psychol- 
ogist, Illinois  Eastern  Hospital,  Kanka- 
kee, 111.,  1897- ;  Editor  of  Child-Study 
Monthly. 

Author  of :  — 

Facilities  in  Experimental  Psychology  at 

the  Various  German  Universities.    Am. 

Jour,  of  Psy.,  Aug.,  1892,  Vol.  4,  pp. 

585-594. 
Pseudo-Chromesthesia,  or  the  Association 

of  Colors  vpith  Words,  Letters,   and 

Sounds.    Ibid.,  Oct.,  1892,  Vol.  5,  pp. 

20-41. 
An  Experimental  Study  of  Simultaneous 

Stimulation  of  the   Sense  of   Touch, 

Jour,  of  Nervoxis  and  Mental  Disease, 

March,  1893 ;  N.  S.,  Vol.  18,  pp.  169- 

184. 
Practical  Lessons   in   Psychology.     The 

Werner  Co.,  Chicago  and  New  York. 

400  pp. 
Laboratory  Psychology  as  applied  to  the 

Study  of  Insanity.     Psychiater,  Vol.  1, 

No.  1. 
Minor  Mental  Abnormalities  in  Children 

as  occasioned  by   Certain  Erroneous 

School  Methods.    Proc.  N.  E.  A. ,  1898, 

pp.  162-172. 

ELLSWORTH   G.  LANCASTER:  — 

B.A.,  Amherst  College,  1885;  M.A., 
ibid.  1888  ;  Teacher,  Elocution  and  Phys- 
ical Culture,  Williston  Seminary,  East- 
hampton,  Mass.,  1885-86;  Student, 
Auburn  Theological  Seminary,  1886-87  ; 
Teacher,  Physical  Culture,  Latin,  and 
German,  Morgan  Park  Military  Academy, 


1887-88  ;  Student,  Chicago  Baptist  Semi- 
nary, 1887-88  ;  Student,  Andover  Theo- 
logical Seminary,  1888-89;  B.D.,  ibid., 
1889 ;  Pastor,  Congregational  Church, 
Ashby,  Mass.,  1889-90;  Principal,  South- 
ern Kansas  Academy,  1890-95  ;  Scholar 
in  Psychology,  Clark  University, 
1895-96;  Fellow,  1896-97;  Ph.D., 
Clark  University,  1897  ;  Instructor  in 
Philosophy  and  Pedagogy,  and  President's 
Assistant,  Colorado  College,  1897-98 ; 
Assistant  Professor,  ibid.,  1898-. 

Author  of :  — 

Psychology  and  Pedagogy  of  Adolescence. 

Pedagogical     Seminary,    July,    1897, 

Vol.  5,  pp.  61-128. 
Warming  Up.     Colorado  College  Studies, 

Nov.,  1898,  Vol.  7,  pp.  16-29. 

JAMES    STEPHEN   LEMON:  — 

B.A.,  Wesleyan  University,  1863  ;  M.A., 
ibid.,  1866;  Principal  of  High  School, 
Brownville,  New  York,  1862;  Assistant  on 
McClintock  and  Strong's  Cyclopaedia  of 
Biblical,  Theological,  and  Ecclesiastical 
Literature,  1859-61 ;  Assistant  on  Strong's 
Concordance  of  the  Bible,  1859-65  ;  Pro- 
fessor of  Physics,  Marion,  N.  Y.,  Institute, 
1863-65  ;  Principal,  Almond  Collegiate  In- 
stitute, 1866  ;  Principal,  Macedon,  N.  Y., 
Academy,  1867;  Rector,  Protestant  Epis- 
copal Church,  1877-;  Scholar  in  Psy- 
chology, Clark  University,  1891-93; 
Student  in  Psychology,  1893-94  ;  Lec- 
turer in  Psychophysics,  Columbian  Uni- 
versity, Washington,  D.  C,  1894-;  Ph.D., 
Columbian  University,  1896  ;  Lecturer 
in  Physiological  Psychology,  Howard 
University,  1897- ;  Member  Society  for 
Philosophical  Inquiry,  Washington,  D.  C; 
Member  American  Anthropological  So- 
ciety. 

Author  of:  — 

Signalling  by  Flashlights.  Troy,  Pa.  ,1874. 

10  pp. 
The  Body  Considered  in  Its  Relation  to  the 

Intellectual  Processes.    Union  Springs, 

N.  Y.,  1875. 
Lists   of   Questions   to   be  Asked   as   to 

Defectives,  etc.,  admitted  to  Cottage 


510 


Titles  of 


Hospitals  for  Children.  Athol,  Mass. 
7  pp. 

Psychic  Effects  of  the  "Weather.  Am.  Jour. 
ofFsy.,  Jan.,  1894,  Vol.  6,  pp.  277-311. 

Requirements  Demanded  for  Official  Rec- 
ognition as  Teachers.  Templeton  Press, 
Templeton,  Mass.,  1898.    13  pp. 

The  Skin  considered  as  an  Organ  of  Sensa- 
tion. Journal  Publishing  Co.,  Gardner, 
Mass.,  1898.     77  pp. 

The  Weather  Idea.  Journal  Publishing 
Co.,  Gardner,  Mass.,  1899.     60  pp. 

Numerous  reviews  and  articles  in  Healthy 
Home,  Cottager,  and  National  Tribune, 
1880-. 

JAMES   E.   LEROSSIGNOL  : — 

B.A.,McGill  University,  1888;  Teacher  in 
Berthelet  School,  Montreal,  1888-89  ;  Stu- 
dent in  Philosophy,  University  of  Leipzig, 
1889-92;  Ph.D.,  University  of  Leipzig, 
1892;  Fellow  in  Psychology,  Clark  Uni- 
versity, May-July,  1892  ;  Professor  of 
Psychology  and  Ethics,  Ohio  University, 
Athens,  1892-94 ;  Professor  of  History  and 
Political  Economy,  University  of  Denver, 
1894- ;  Member  of  :  American  Economic 
Association,  American  Academy  of  Polit- 
ical and  Social  Science,  American  His- 
torical Association. 

Author  of :  — 

The  Ethical  Philosophy  of  Samuel  Clarke. 

G.  Kreysing,  Leipzig,  1892.     97  pp. 
The  Training  of  Animals.     Am.  Jour,  of 

Psy.,  Nov.,  1892,  Vol.  5,  pp.  205-213. 
Malevolence  in  the  Lower  Animals.     Ohio 

University  Bulletin,  Sept.,  1893,  Vol.  1, 

pp.  1-9. 
The  Expression  of  Anger.     Transactions 

of  the  Ohio  College  Association,  1894, 

pp.  40-49. 
Spinoza  as  a  Biblical  Critic.      Canadian 

Methodist  Beview,  Jan.-Feb.,  1895,  Vol. 

7,  pp.  52-60. 

JAMES   H.  LEUBA  :  — 

B.S.,  University  of  Neuch§,tel,  Switzer- 
land, 1886  ;  Ph.B.,  Ursiuus  College,  1888  ; 
Instructor  in  French  and  German,  St. 
Mark's     School,     Southborough,     Mass., 


1891-92 ;  Scholar  in  Psychology,  Clark 
University,  1892-93;  Fellow,  1893- 
95;    Ph.D.,   Clark  University,    1895; 

Professor  of  Psychology  and  Pedagogy, 
Bryn  Mawr  College,  1897- ;  Universities 
of  Leipzig,  Gottingen,  Heidelberg,  and 
Paris,  1897-98  ;  Member  of  the  American 
Psychological  Association. 

Author  of :  — 

A  New  Instrument  for  Weber's  Law  ;  with 
Indications  of  a  Law  of  Sense  Memory. 
Am.  Jour,  o/ Psy.,  April,  1893,  Vol.  5, 
pp.  370-384. 

National  Destruction  and  Construction  in 
Prance  as  seen  in  Modern  Literature 
and  in  the  Neo-Christian  Movement. 
Ibid.,  July,  1893,  Vol.  5,  pp.  496-539. 

A  Study  in  the  Psychology  of  Religious 
Phenomena.  Ibid.,  April,  1896,  Vol. 
7,  pp.  309-385. 

The  Psycho-Physiology  of  the  Moral  Im- 
perative. Ibid.,  July,  1897,  Vol.  8,  pp. 
528-559. 

On  the  Validity  of  the  Griesbach  Method 
of  Determining  Fatigue.  Psychologi- 
cal Beview,  Nov.,  1899,  Vol.  6,  pp. 
573-598. 

FRANK   R.  LILLIE:  — 

Assistant  in  Biology, University  of  Toronto, 
1890-91;  B.A.,  ibid.,  1891;  Fellow  in 
Morphology,  Clark  University,  1891- 

92;  Fellow  in  Zoology,  University  of  Chi- 
cago, 1892-93 ;  Reader  in  Embryology, 
ibid.,  1893-94;  Ph.D.,  University  of  Chi- 
cago, 1894;  Instructor  in  Zoology,  Uni- 
versity of  Michigan,  1894-99;  Professor 
of  Biology,'Vassar  College,  1899-;  Member 
American  Society  of  Morphologists;  Mem- 
ber Michigan  Academy  of  Sciences. 

Author  of :  — 

Preliminary  Account  of  the  Embryology 
of  Unio  complauata.  Jour,  of  Morph., 
Aug.,  1893, Vol.  8,  pp. 569-578,  1  plate. 

The  Embryology  of  the  Unionidte,  a  Study 
in  Cell-Lineage.  Ibid.,  Jan.,  1895 ;  Vol. 
10,  pp.  1-100,  6  plates. 

On  the  Smallest  Parts  of  Stentor  Capable 
of  Regeneration.     A  Contribution  on 


Published  Papers. 


511 


the  Limit  of  Divisibility  of  Living  Mat- 
ter. Ibid. ,  May,  1896,  Vol.  12,  pp.  239- 
249. 

On  the  Effect  of  Temperature  on  the  De- 
velopment of  Animals.  (With  F.  P. 
Knowlton.)  Zoological  Bulletin.,  Dec, 
1897,  Vol.  1,  pp.  179-193. 

On  the  Origin  of  the  Centres  of  the  First 
Cleavage  Spindle  in  Unio  complanata. 
Science,  March  5,  1897,  N.  S.,  Vol.  5, 
pp.  389-390. 

Centrosome  and  Sphere  in  the  Egg  of  Unio. 
Zoological  Bulletin,  May,  1898, Vol.  1, 
pp.  265-274. 

Hertwig's  "Zelle  und  Gewebe,"  Vol.  2. 
Science,  Oct.  14, 1898,  N.  S.,Vol.  8,  pp. 
517-520. 

Adaptation  in  Cleavage.  "Woods  Holl 
Biological  Lectures,  1898.  Ginn  &  Co., 
Boston.     (In  press.) 

ERNEST   H.  LINDLEY:  — 

A.  B.,  Indiana  University,  1893;  AM.,ihid., 
1894  ;  Instructor  in  Philosophy,  iftid.,  1893- 
95 ;  Fellow  in  Psychology,  Clark 
University,  1895-97;  Ph.D.,  Clark 
University,  1897 ;  Universities  of  Jena, 
Leipzig,  and  Heidelberg,  1897-98 ;  Asso- 
ciate Professor  of  Psychology,  Indiana 
University,  1898- ;  Member  American 
Psychological  Association. 

Author  of :  — 

A  Preliminary  Study  of  Some  of  the  Mo- 
tor Phenomena  of  Mental  Effort.  Am. 
Jour,  of  Psy.,  July,  1896,  Vol.  7,  pp. 
491-517. 

Some  Mental  Automatisms.  (With  G.  E. 
Partridge.)  Pedagogical  Seminary, 
July,  1897,  Vol.  5,  pp.  41-60. 

A  Study  of  Puzzles  with  Special  Reference 
to  the  Psychology  of  Mental  Adapta- 
tion. Am.  Jour,  of  Psy.,  July,  1897, 
Vol.  8,  pp.  431-493. 

Ueber  Arbeit  und  Ruhe.  Psychologische 
Arbeiten,  herausg.  von  E.  Kraepelin. 
Heidelberg.     (In  press.) 

C.  E.  LINEB  ARGER  :  — 

A.B. ,  Northwestern  University,  1888 ; 
Student,  Chicago  Medical  College,  1888- 


89  ;  Student,  Universities  of  Tubingen  and 
Paris,  1889-91 ;  Fellow  in  Chemistry, 
Clark  University,  1891 ;  Instructor  in 
Chemistry,  North  Division  High  School, 
Chicago,  1891-93 ;  Student,  University  of 
Gottiugen,  1893-94 ;  Student,  School  of 
Mines,  Paris,  1894 ;  Instructor  in  Chem- 
istry and  Physics,  South  Division  High 
School,  Chicago,  1894-96 ;  Instructor  in 
Chemistry  and  Physics,  Lake  View  High 
School,  Chicago,  1896-99;  Member  of: 
American  Chemical  Society,  Chemical 
Society  of  Paris,  German  Electro- 
chemical Society. 

Author  of:  — 

An  Examination  of  Fusel  Oil.  (With 
J.  H.  Long.)  Jour,  of  Anal.  Chem., 
1890,  Vol.  4,  p.  5. 

Sur  I'Hydroxanthranol.  Bull.  d.  I.  Soc. 
Chimique,  1891,  Vol.  6,  p.  92. 

The  Action  of  Benzene  on  Benzal  Chloride 
in  the  Presence  of  Aluminium  Chloride. 
Am.  Chem.  Jour.,  1891, Vol.  13,  p.  556. 

The  Reaction  between  Triphenylmethane 
and  Chloroform  in  the  Presence  of 
Aluminium  Chloride.     Ibid.,  p.  553. 

On  Disulphotetraphenylene.  Jour.  Am. 
Chem.  Soc,  Vol.  13,  p.  270. 

A  Rapid  Dialyzer.  Jour,  of  Anal.  Chem., 
1892,  Vol.  6,  p.  91. 

On  the  Nature  of  Colloid  Solutions.  Am. 
Jour,  of  Sci.,  1892,  Vol.  43,  p.  218. 

The  Molecular  Masses  of  Dextrine  and 
Gum  Arabic  as  determined  by  their 
Osmotic  Pressures.     Ibid.,  p.  428. 

On  the  Formation  of  Layers  in  Solutions 
of  Salts  in  Mixtures  of  Water  and 
Organic  Liquids.  Am.  Chem.  Jour., 
1892,  Vol.  14,  p.  380. 

On  the  Relations  between  the  Surface 
Tensions  of  Liquids  and  their  Chemi- 
cal Constitution.  A7n.  Jour,  of  Sci., 
1892,  Vol.  44,  p.  83. 

On  the  Influence  of  the  Concentration  of 
the  Ions  on  the  Intensity  of  Color  of 
Solutions  of  Salts  in  Water.  Ibid.,  p. 
416. 

The  Dissociation  of  Salts  into  their  Ions 
by  Water  of  Crystallization.  Am. 
Chem.  Jour.,  1892,  Vol.  14,  p.  604. 


512 


Titles  of 


On  the  Application  of  the  Friedel-Craffts 
Reaction  to  Syntheses  in  the  Anthra- 
cene Series.     Ibid.,  p.  602. 

On  the  Preparation  and  Constitution  of 
Paraanthracene.     Ibid.,  p.  597. 

A  Definition  of  Solutions.  Science,  1892, 
Vol.  20,  p.  352. 

The  Solubility  of  Triphenylmethane  in 
Benzene.  Am.  Chem.  Jour.,  1893, 
Vol.  15,  p.  4.5. 

The  Hydrates  of  Manganous  Sulphate. 
Ibid.,  1893,  Vol.  15,  p.  225. 

On  the  Existence  of  Double  Salts  in  Solu- 
tion.    Ibid.,  1893,  Vol.  15,  p.  337. 

An  Isothermal  Curve  of  Solubility  of 
Mercuric  and  Sodium  Chlorides  in 
Acetic  Ether.  Ibid.,  1894,  Vol.  16, 
p.  215. 

The  Benzoyl  Halogen  Amides.  Ibid., 
1894,  Vol.  16,  p.  218. 

Ueber  die  Bestimmung  kleiner  Dissocia- 
tionsspannungen  speciell  Krystallwas- 
serhaltiger  Salze.  Zeits.  f.  phys. 
Chemie,  1894,  Vol.  13,  p.  500. 

Some  Modifications  of  Beckmann's  Ebul- 
lioscopic  Apparatus.  Chemical  Neios, 
1894,  Vol.  69,  p.  279. 

The  Boiling  Points  of  Dilute  Solutions  of 
"Water  in  Alcohol  and  in  Ether.  Ibid. , 
p.  613. 

On  the  Application  of  the  Schroeder-Le- 
Chatelier  Law  of  Solubility  to  Solutions 
of  Salts  in  Organic  Liquids.  Am. 
Jour,  of  Sci.,  1895,  Vol.  49,  p.  48. 

The  Combination  of  Sulphur  with  Iodine. 
Am.  Chem.  Jour.,  1895,  Vol.  17,  p. 
33. 

On  Some  Experiments  in  the  Anthracene 
Series.  Jour.  Ain.  Chem.  Soc,  1895, 
Vol.  17,  p.  351. 

On  the  .Reaction  between  Zinc  Sulphate 
and  Potassium  Hydroxide.  Ibid.,  p. 
358. 

On  Some  Relations  between  Temperature, 
Pressure,  and  Latent  Heat  of  Vapor- 
ization. Am.  Jour,  of  Sci.,  1895, Vol. 
49,  p.  380. 

On  the  Vapor  Tensions  of  Mixtures  of 
Volatile  Liquids.  Jour.  Am.  Chem. 
Soc,  1895,  Vol.  17,  p.  580. 

On  the  Formation  of  Layers  in  Mixtures 


of  Acetic  Acid  and  Benzene.  Ibid. ,  p. 
932. 

On  the  Heat  Effect  of  mixing  Liquids. 
Physical  Review,  1896,  Vol.  3,  p.  418. 

On  the  Specific  Gravities  of  Mixtures  of 
Normal  Liquids.  Am.  Chem.  Jour., 
1896,  Vol.  18,  p.  428. 

A  Rapid  Method  of  determining  the  Mo- 
lecular Masses  of  Liquids  by  Means  of 
their  Surface  Tensions.  Jour.  Am. 
Chem.  Soc,  1896,  Vol.  18,  p.  514. 

On  the  Reaction  between  Carbon  Tetra- 
chloride and  the  Oxides  of  Niobium 
and  Tantalum.  (In  collaboration  with 
M.  Delafontaine.)     Ibid.,  p.  32. 

Ueber  die  Dielektricitatskonstanten  von 
Fliissigkeitsgemischen.  Zeitschr.  f. 
phys.  Chemie,  1896,  Vol.  20,  p.  131. 

An  Apparatus  for  the  Rapid  Determina- 
tion of  the  Surface  Tensions  of  Liquids. 
Am.  Jour.  Sci.,  1896,  Vol.  2,  p.  108. 

On  the  Surface  Tension  of  Mixtures  of 
Normal  Liquids.    Ibid.,  p.  226. 

On  the  Viscosity  of  Mixtures  of  Liquids. 
Ibid.,  p.  331. 

The  Phase  Rule.  By  Wilder  D.  Bancroft. 
Review.     Monist,  1897,  Vol.  7,  p.  634. 

Grundziige  einer  thermodynamischen 
Theorie  elektrochemischer  Krafte.  By 
Alfred  H.  Bucherer.  Review.  Ibid., 
p.  635. 

The  Phase  Rule.  By  "Wilder  D.  Bancroft. 
Review.  Jour.  Am.  Chem.  Soc,  1897, 
Vol.  19,  p.  767. 

The  Surface  Tensions  of  Aqueous  Solu- 
tions of  Oxalic,  Tartaric,  and  Citric 
Acids.     Ibid.,  1898,  Vol.  20,  p.  128. 

An  Outline  of  the  Theory  of  Solution  and 
its  Results.  By  J.  Livingston  R.  Mor- 
gan. Review.  Ibid.,  1898,Yo\.  20,  p. 
153. 

The  Principles  of  Mathematical  Chemis- 
try. By  J.  Livingston  R.  Morgan. 
Review.     Ibid.,  1898,  Vol.  20,  p.  155. 

On  the  Speed  of  Coagulation  of  Colloid 
Solutions.  Ibid.,  1898,  Vol.  20,  p. 
375. 

Text-book  of  Physical  Chemistry.  By 
Clarence  L.  Speyers.  Review.  Ibid., 
1898,  Vol.  20,  p.  389. 

On  a  Balance  for  Use  in  Courses  in  Ele- 


Published  Papers. 


513 


mentary  Chemistry.     76id.,  1899,  "Vol. 

21,  p.  31. 
The  Surface  Tension  of  Aqueous  Solutions 

of    Alkaline   Chlorides.     Ihid.,   1899, 

Vol.  21,  p.  327. 
A  Simple   Voluminometer.     Ibid.,    1899, 

Vol.  21,  p.  435. 
The  Elements  of  Differential  and  Integral 

Calculus.    (In  collaboration  with  J.  W. 

A.  Young.)     1899,  D.  Appleton  &  Co. 

SIDNEY  J.   LOCHNER:  — 

A.B.,  Union  College,  1890;  A.M.,  ibid., 
1892  ;  First  Assistant  in  Astronomy,  Dud- 
ley Observatory,  Albany,  N.  Y.,  1889-92  ; 
Fellow  in  Physics,  Clark  University, 
Oct.,  1892-May,  1893  ;  Assistant,  Har- 
vard Observatory,  1893  ;  Admitted  as  At- 
torney at  Law,  Detroit,  Mich.,  Dec, 
1893;  Professor  of  Physics  and  Mathe- 
matics, Delaware  Literary  Institute, 
Franklin,  N.  Y.,  1894-. 

Author  of:  — 

On  the  Elongation  Produced  in  Soft  Iron 
by  Magnetism.  Fhil.  Magazine,  Dec, 
1893,  Fifth  Series,  Vol.  36,  pp.  498- 
507. 

Modern  Scientific  Investigations.  Union 
College  Concordensis,  1894. 

WILLIAM  E.  LOCKWOOD:  — 

Ph.B.,  Sheffield  Scientific  School,  Yale 
University,  1883;  M.D.,  ibid.,  1885 ;  in- 
structor in  Chemistry,  ibid.,  1885-86  ;  In- 
structor and  Demonstrator  in  Physiology, 
ibid.,  1887-91  ;  Fellow  in  Physiology, 
Clark  University,  1891-92. 
Died  at  Redlands,  Cal.,  June  23,  1897. 

Author  of :  — 

The  New  Haven  Water  Supply  :  A  Criti- 
cism of  the  Results  of  Analyses  of 
this  Water,  as  given  by  Dr.  Arthur  J. 
Wolff,  in  the  Report  of  the  Connecticut 
State  Board  of  Health  for  1885.  (With 
Herbert  E.  Smith,  M.D.)  New  Haven. 
6  pp. 

Report  of  the  Analyses  of  One  Hundred 
and  Ten  Well  Waters,  collected  in 
New  Haven.  (With  Herbert  E.  Smith, 
M.D.)      Report    of   the    Connecticut 


State  Board  of  Health,  1886,  pp.  259- 
269. 
Some  Hints  for  the  Physician  concerning 
Urinary  Analysis.  3Iedical  Register, 
Philadelphia,  March  19,  1887,  Vol.  1, 
pp.  169-174. 

MORRIS  LOEB  :  — 

A.B.,  Harvard  University,  1883;  Ph.D., 
University  of  Berlin,  1887  ;  Assistant  to 
Professor  Wolcott  Gibbs,  1888-89  ;  Do- 
cent  in  Physical  Chemistry,  Clark 
University,  1889-91 ;  Professor  of 
Chemistry,  New  York  University,  N.  Y. 
City,  1891-. 

Author  of :  — 

Ueber  die  Einwirkung  von  Phosgen  auf 
Aethenyldiphenyldiamin,  Ber.  d. 
deut.  chem.  Gesellschaft,  Aug.,  1885, 
Vol.  18,  pp.  2427-2428. 

Ueber  Amidinderivate.  Ibid. ,  Aug. ,  1886, 
Vol.  19,  pp.  2340-2444. 

Das  Phosgen  und  seine  Abkommlinge. 
Berlin,  March  15,  1887.     51  pp. 

The  Molecular  Weight  of  Iodine  in  its 
Solutions.  Jour,  of  Chem.  Soc, 
Trans.,  1888,  Vol.  53,  pp.  805-812. 
Also  Zeits.  f.  physikalische  Chemie, 
July,  1888,  Vol.  2,  pp.  606-612. 

The  Use  of  Aniline  for  Absorbing  Cyano- 
gen in  Gas  Analysis.  Jour,  of  Chem. 
Soc,  Trans.,  1888,  Vol.  53,  pp.  812- 
814. 

The  Rates  of  Transference  and  the  Con- 
ducting Power  of  Certain  Silver  Salts. 
(With  W.  Nernst. )  Am.  Chem.  Jour. , 
Feb.,  1889,  Vol.  11,  pp.  106-121.  Also 
Zeits.  f.  physikalische  Chemie,  Nov., 
1888,  Vol.  2,  pp.  948-963. 

Is  Chemical  Action  Affected  by  Magnet- 
ism? Am.  C/iejn.  Jbwr.,  March,  1891, 
Vol.  13,  pp.  145-153. 

WARREN  P.  LOMBARD  :  — 

A.B.,  Harvard  University,  1878;  M.D., 
Harvard  Medical  School,  1881  ;  University 
of  Leipzig,  1882-85;  Assistant  in  Physi- 
ology, College  of  Physicians  and  Surgeons, 
New  York  City,  1888-89  ;  Assistant  Pro- 
fessor   of  Physiology,   Clark  Univer- 


514 


Titles  of 


sity,  1889-92 ;  Professor  of  Physiology, 
University  of  Michigan,  1892- ;  Member 
American  Physiological  Society. 

Author  of :  — 

Beitrage  zur  Theorie  der  Warmeempfin- 
dung.  Vorlaufige  Mitteilung.  Cen- 
tralbl.  f.  d.  Med.  JVissensch.,  1883, 
Vol.  21,  pp.  577-579. 

Die  raumliche  und  zeitliche  Auf  einander- 
folge  reflectorisch  contrahirter  Mus- 
keln.  Ai'ch.  f.  Anat.  u.  Physiologie, 
Physiol.  Abthl.,  1885,  pp.  408-489. 

Is  the  "Knee-jerk"  a  Reflex  Act?  Am. 
Jour,  of  Med.  Sciences,  Jan.,  1887. 

The  Variations  of  the  Normal  ' '  Knee- 
jerk."  Am.  Jour,  of  Fsy.,  Nov.,  1887, 
Vol.  1,  pp.  5-71. 

Die  Variationen  des  normalen  Kniestosses. 
Arch,  f  Anat.  u.  Physiologie.,  Suppl. 
Band,  1889,  pp.  292-335,  10  pis. 

On  the  Nature  of  the  "  Knee-jerk."  Jour, 
of  Physiology,  Feb.,  1889,  Vol.  10,  pp. 
122-148. 

The  Effect  of  Fatigue  on  Voluntary  Mus- 
cular Contraction.  Am.  Jour,  of  Psy., 
Jan.,  1890,  Vol.  3,  pp.  24-42. 

Effet  de  la  fatigue  sur  la  contraction  mus- 
culaire  volontaire.  Arch.  Ital.  de  Biol- 
ogie,  1890,  Vol.  13,  pp.  371-381. 

Alterations  in  the  Strength  which  occur 
during  Fatiguing  Voluntary  Muscular 
Work.  Jour,  of  Physiology,  Jan., 
1893,  Vol.  1-4,  pp.  97-124. 

General  Physiology  of  Miiscle  and  Nerve. 
Chapter  11.,  Howell's  ^?)i.  Text  Book 
of  Physiology.  W.  B.  Saunders,  Phila- 
delphia, 1896.    pp.  32-151. 

PRANK  H.   LOUD  :  — 

A.B.,  Amherst  College,  1873  ;  Walker  In- 
structor in  Mathematics,  ibid.,  1873-76; 
Professor  of  Mathematics,  Colorado  Col- 
lege, 1877- ;  Director  of  State  Weather 
Service,  Colorado,  1889-90 ;  Scholar 
in  Mathematics,  Clark  University, 
1890-91. 

Author  of :  — 

A  Rigorous  Elementary  Proof  of  the 
Binominal  Theorem.  Col.  College 
Studies,   1890,  pp.  7-15. 


On  Certain  Cubic  Curves.  Ibid.,  1890,  p. 
16. 

The  Elliptic  Functions  Defined  Indepen- 
dently of  the  Calculus.  Ibid.,  1891, 
pp.  48-81. 

ELWYN   N.  LOVEWELL:  — 

Ph.B.,  University  of  Vermont,  1898 
(Double  Honors)  ;  Scholar  in  Mathe- 
matics, Clark  University,  1898-99. 

GEORGE   "W.  A.  LUCKEY  :  — 

Teacher  in  Public  Schools  of  Indiana, 
1874-78 ;  Superintendent  of  Schools, 
Adams  Co.,  Ind.,  1878-82  ;  Superinten- 
dent of  Schools,  Decatur,  Ind.,  1882- 
87  ;  Supervising  Principal,  Ontario,  Cal., 
1888-92 ;  Non-Resident  Student,  Univer- 
sity of  City  of  New  York,  1889-92  ;  Stu- 
dent in  Pedagogy  and  Psychology,  Leland 
Stanford  Jr.  University,  1892-94  ;  A.B., 
ibid.,  1894;  Fellow  in  Psychology, 
Clark  University,  1894-95  ;  Associate 
Professor  of  Pedagogy,  University  of  Ne- 
braska, 1895-96 ;  Professor  of  Pedagogy, 
ibid.,  1896- ;  Editor  of  the  Child  Study 
Department,  Northwestern  Monthly,  1895- 
99. 

Author  of :  — 

Comparative  Observations  on  the  Indirect 
Color  Range  of  Children,  Adults,  and 
Adults  Trained  in  Color.  Am.  Jour, 
of  Psy.,  Jan.,  1895,  Vol.  6,  pp.  489- 
504. 

Some  Recent  Studies  of  Pain.     Ibid.,  Oct. , 

1895,  Vol.  7,  pp.  108-123. 

Child  Study  in  its  Effects  upon  the 
Teacher.     Child  Study  Monthly,  Feb., 

1896,  Vol.  1,  pp.  230-247. 
Children's  Interests.     Northw.  3Ionthly, 

1896-97,  Vol.  7,  pp.  67,  96,  133,  156, 

221,  245,  306,  and  335. 
Practical  Results  Obtained  through  the 

Study  of  Children's  Interests.     Proc. 

N.  E.  A.,  1897,  pp.  284-288  ;  also  Jour. 

of  Ed.,  Apr.  8,  1897,  Vol.  45,  p.  222. 
Lines  of  Child   Study  for  the   Teacher. 

Educational  Beview,  Nov.,  1897,  Vol. 

14,  pp.  340-347  ;  also  Proc.  N.  E.  A., 

1897,  pp.  826-833. 


Published  Papers. 


515 


A  Brief  Survey  of  Child  Study.  North- 
western Jour,  of  Ed.,  July,  1896,  Vol. 
7,  pp.  2-9. 

Methods  Pursued  in  Child  Study.  Ibid., 
pp.  33-35. 

The  Best  Works  on  Child  Study.  Ibid., 
pp.  48-53. 

The  Development  of  Moral  Character. 
Proc.  iV.  E.  A.,  1899. 

HERMAN   T.  LUKENS  :  — 

A.B.,  University  of  Pennsylvania,  1885  j 
A.M.,  ibid.,  1888  ;  Student  in  Halle,  Jena, 
and  Berlin,  1888-91 ;  Ph.D.,  University  of 
Jena,  1891 ;  Instructor  in  Biology,  N.  W. 
Division  High  School,  Chicago,  1891-94  ; 
Honorary  Fellow  in  Psychology, 
Clark  University,  1894-95  ;  Docent 
in  Pedagogy,  1895-  ;  Lecturer  in 
Education,  Bryn  Mawr  College,  1896-97  ; 
Visit  to  Europe  to  study  Education, 
1897-98 ;  Head  Training  Teacher,  S.  W. 
State  Normal  School,  California,  Pa., 
1898-. 

Author  of :  — 

Herbart's  Psychological  Basis  of  Teach- 
ing. Part  II  of  Th.  B.  Noss's  Outlines 
of  Psychology  and  Pedagogy,  Pitts- 
burg, 1890. 

Die  Vorstellungsreihen  und  ihre  padago- 
gische  Bedeutung.  Giitersloh,  Prussia, 
1892. 

A  Portion  of  the  Translation  of  Lange's 
Apperception.  Edited  by  Charles  De 
Garmo.  D.  C.  Heath  &  Co.,  Boston, 
1893.     279  pp. 

The  Connection  between  Thought  and 
Memory.  Based  on  Dorpfeld's  Den- 
ken  und  Geddchtnis.  D.  C.  Heath  & 
Co.,  Boston,  1895.     179  pp. 

The  Correlation  of  Studies.  Educational 
Beview,  Nov.,  1895,  Vol.  10,  pp.  364- 
383. 

Correlation.  Jour,  of  Ed.,  May  9  and 
June  20,  1895,  Vol.  41,  pp.  311-312  ; 
Vol.  42,  p.  15. 

A  Point  of  Difference  between  Race  and 
Individual  Development.  Second  Her- 
bartian  Yearbook,  1896. 

Preliminary  Report  on  the  Learning  of 


Language.     Pedagogical     Seminary, 

June,  1896,  Vol.  3,  pp.  424-460. 
A  Study  of  Children's  Drawings  in  the 

Early  Years.     Ibid.,  Oct.   1896,  Vol. 

4,  pp.  79-110. 
Child  Study  for  Superintendents.    Edu- 
cational Beview,  Feb.,  1897,  Vol.  13, 

pp.  105-120. 
Honorary  Degrees  in  the  United  States. 

Ibid.,  June,  1897,  Vol.  14,  pp.  8-16. 
Language    Defects.     Northw.    Monthly, 

July,  1897,  Vol.  8,  pp.  39-44. 
The  Vital  Question  in  the  Curriculum. 

Education,  Sept.,   1897,  Vol.  18,  pp. 

19-29. 
Die  Entwickelungsstufen  beim  Zeichnen. 

Kinderfehler,  Dec,  1897,  Vol.  2,  pp. 

166-170. 
Malendes     Zeichnen.      Aus     dem    pad. 

Univ.- Seminar  Jena,  VII.,  1897. 
The   School   Fatigue    Question  in    Ger- 
many.    Educational  Beview,   March, 

1898,  Vol.  15,  pp.  246-254. 
The  Method  of  Suggestion  in  the  Cure  of 

Faults.     Northwestern  Monthly,  May, 

1898,  Vol.  8,  pp.  592-595. 
The  School  and  Real  Life.     iV.  Y.  School 

Jour.,  Oct.  1,  1898,  Vol.  57,  pp.  277- 

279. 
Notes    Abroad.     Pedagogical  Seminary, 

Oct.,  1898,  Vol.  6,  pp.  114-125. 
A  School-Garden  in  Thuringia.     Educa- 
tional Beview,  March,  1899,  Vol.   17, 

pp.  237-241. 
Mental  Fatigue.    Am.  Phys.  Ed.  Beview, 

March  and  June,    1899,  Vol.  4,   pp. 

19-29,  121-135. 
The    Joseph    Story.      N.    Y.    Teachers'' 

Magazine,   April,    1899,   Vol.   1,    pp. 

331-334. 
Drawing  in  the  Early  Years.     Proc.  N. 

E.  A.,  1899. 

ALEXANDER   G.  McADIE:  — 

A.B.,  College  of  City  of  New  York,  1881 ; 
A.M.,  ibid.,  1884  ;  Student,  Harvard  Uni- 
versity, 1882-85;  A.M.,  ibid.,  1885  ;  Phys- 
ical Laboratory,  U.  S.  Signal  Office,  1886- 
87  ;  Fellow  in  Physics,  Clark  Univer- 
sity, 1889-90;  U.  S.  Signal  Office, 
Washington,  1890-91 ;  U.  S.  Weather  Bu- 


516 


Titles  of 


reau,  Washington,  1891-95;  Hodgkins 
Medal  and  Honorable  Mention,  Smith- 
sonian Institution,  1895;  Local  Forecast 
Official,  New  Orleans,  1898-09 ;  Forecast 
Official,  San  Francisco,  1899-;  Honorary 
Lecturer  in  Meteorology,  University  of 
California;  Director,  California  Climate 
and  Crop  Service. 

Author  of :  — 

On  the  Aurora.  U.  S.  Signal  Service 
Note,  No.  18,  pp.  21,  5  maps,  12  charts. 

Protection  against  Lightning.  Am.  3Iet. 
Jour.,  June,  1885,  Vol.  2,  pp.  60-66. 

Atmospheric  Electricity  at  High  Altitudes. 
Proc.  Am.  Academy,  1885,  Vol.  13,  pp. 
129-134. 

Electrometer  Work.  Monthly  Weather 
Bevieiv,  1886-87,  Vol.  14,  pp.  166-167. 

Observations  of  Atmospheric  Electricity. 
Am.  Met.  Jour.,  March,  1887,  Vol.  3, 
pp.  523-531 ;  April,  1887,  Vol.  3,  pp. 
551-561 ;  May,  1887,  Vol.  4,  pp.  21-31. 

William  Ferrell.  Ibid.,  Feb.,  1888,  Vol. 
4,  pp.  441-449. 

Lightning  and  the  Electricity  of  the  At- 
mosphere. Ibid.,  May,  1889,  Vol.  6, 
pp.  1-4. 

Tornadoes.  Prize  Essay.  Ibid.,  Vol.  7, 
pp.  179-192. 

Mean  Temperatures  in  the  United  States. 
Professional  Paper,  U.  S.  Signal  Office, 
June,  1891.    Washington,  1891.    45  pp. 

Franklin's  Kite  Experiment.  Am.  Met. 
Jour.,  July,  1891,  Vol.  8,  pp.  97-108. 

Shall  We  erect  Lightning  Rods?  Ibid., 
July,  1892,  Vol.  9,  pp.  60-66. 

Experiments  in  Atmospheric  Electricity. 
Annals  of  Observatory  of  Harvard  Col- 
lege, Vol.  40,  Part  1,  pp.  53-58. 

Experiments  in  Atmospheric  Electricity  at 
Blue  Hill,  1892.  Annals  of  Observa- 
tory of  Harvard  College,  Vol.  40,  Part 
2,  pp.  120-124. 

Energy  of  a  Flash  of  Lightning.  Proc.  of 
the  Internal.  Met.  Congress,  Chicago, 
1893,  Paper  5,  Part  1,  pp.  18-21. 

Utilization  of  Cloud  Observations.  Ibid., 
Paper  6,  Part  1,  pp.  21-26. 

Protection  from  Lightning.  U.  S.  Weather 
Bureau,  Bulletin  No.  15,  1894. 


A  Colonial  Weather  Service.  Pop.  Set. 
3Io.,  July,  1894,  Vol.  45,  pp.  331-337. 

The  Storage  Battery  of  the  Air.  Harper'' s 
Magazine,  July,  1894,  Vol.  89,  pp.  216- 
219. 

New  Cloud  Classifications.  Proc.  Phil. 
Soc.  of  Washington,  March  2,  1895, 
Vol.  13,  pp.  77-86. 

The  Work  and  Equipment  of  an  Aero- 
Physical  Laboratory.  Smithsonian  In- 
stitution, 1895.  30  pp.  Smithsonian 
Miscellaneous  Collections,  Vol.  39,  No. 
1077. 

Fog  Possibilities.  Harper''s  Magazine, 
Jan.,  1897,  Vol.  94,  pp.  263-266. 

What  is  an  Aurora  ?  Century  3Iagazine, 
Oct.,  1897,  Vol.  54,  pp.  874-878. 

Franklin's  Kite  Experiments.  Pop.  Set. 
Mo.,  Oct.  1897,  Vol.  51,  pp.  739-747. 

Needless  Alarm  dui'ing  Thunder-storms. 
Century  3Iagazine,  Aug.,  1899,  Vol.  58, 
pp.  604-605. 

FRANK   H.  McASSEY:  — 

A.B.,  Ripon  College,  Ripon,  Wis.,  1897; 
Scholar  in  Psychology,  Clark  Univer- 
sity, 1898-99. 

J.  F.  Mcculloch  : — 

A. B.,  Adrian  College,  1883 ;  A.M.,  ibid., 
1889;  Ph.B.,  ibid.,  1884;  Assistant  Pro- 
fessor of  Mathematics,  ibid.,  1885-87  ;  In- 
structor in  Mathematics,  University  of 
Michigan,  1887-88 ;  Assistant  Professor 
of  Mathematics,  Adrian  College,  1888-89  ; 
Fellow  in  Mathematics,  Clark  Univer- 
sity, 1889-90;  President,  Adrian  Col- 
lege, 1890-93 ;  Pastor  of  M.  P.  Church, 
Fairmont,  W.  Va.,  1893-94;  Editor,  Our 
Church  Becord,  Greensboro,  N.  C,  1894-. 

Author  of :  — 

Rolle's  Theorem  extended.     Annals  of 

Mathematics,  Vol.  4,  p.  5. 
A  Theorem  in  Factorials.     Ibid.,  Vol.  4, 

p.  161. 

ARTHUR  MacDONALD:  — 

A.B.,  University  of  Rochester,  1879 ;  A.M., 
ibid.,  1883;  Union  Theological  Seminary, 
1880-83 ;  Graduate  Student,  Harvard  Uni- 
versity, 1883-85;  Fellow,  Johns  Hopkins 


Published  Pajjers. 


517 


University,  1885;  Universities  of  Berlin, 
Leipzig,  Paris,  and  Ziirich,  1885-88 ;  Do- 
cent  in  Ethics,  Clark  University ,  1889- 
91 ;  Specialist  in  Education  as  related  to 
the  Abnormal  and  Weakling  Classes,  U.  S. 
Bureau  of  Education,  1891- ;  U.  S.  Dele- 
gate, International  Criminal  Congress, 
Brussels,  1892 ;  International  Psychological 
Congress,  London,  1893 ;  International  De- 
mographical  Congress,  Budapest,  1894. 

Author  of:  — 

Ethics  as  Applied  to  Criminology.  Jour, 
of  Mental  Science,  Jan.,  1891,  Vol.  37, 
pp.  10-16,  and  Open  Court,  July,  1891. 

Alcoholism.  Medico-Legal  Journal,  June, 
1891. 

Criminal  Aristocracy,  or  the  Maffia.  Med- 
ico-Legal Journal,  June,  1891,  Vol.  9, 
pp.  21-26. 

Criminology.  With  an  Introduction  by  C. 
Lombroso,  with  Bibliography.  Funk  & 
Wagnalls  Co. ,  New  York,  1894.  416  pp. 

Abnormal  Man.  Being  Essays  on  Educa- 
cation  and  Crime  and  Related  Subjects, 
with  Digests  of  Literature  and  a  Bibli- 
ography. U.  S.  Bureau  of  Education, 
Washington,  1893.     445  pp. 

Le  Criminel-Type  dans  quelques  formes 
graves  de  la  Criminality.  Bibliographic 
de  Sexualite  Pathologique.  Un  volume 
in  8°  illustr^  de  Portraits.  A  Storck, 
Lyon  et  G.  Masson,  Paris,  1895.  300  pp. 

Education  and  Patho-Social  Studies.  Re- 
print from  Annual  Eeport  of  U.  S. 
Commissioner  of  Education  for  1893- 
94,  Washington,  D.  C,  1896.     67  pp. 

^mile  Zola:  a  Psycho-Physical  Study  of 
Zola's  Personality.  Reprint  from  Open 
Court,  August,  1898.    18  pp. 

Experimental  Study  of  Children,  including 
Anthropometrical  and  Psycho-Physical 
Measurements,  with  a  Bibliography. 
Reprint  from  Annual  Eeport  of  U.  S. 
Commissioner  of  Education  for  1897- 
98,  Washington,  D.  C,  1899,     325  pp. 

Ueber  Korpermessungen  an  Kindern. 
Deuts.  Zeits.  f.  Ausldndisches  Unter- 
richtsioesen,  July,  1899,  Vol.  4,  pp. 
253-266. 

Abnormal  Children.     (In  press.) 


JOHN   McGOWAN:  — 

B.  A.,  University  of  Toronto,  1888 ;  Fellow 
in  Mathematics,  ibid.,  1888-91;  Scholar 
in  Mathematics,  Clark  University, 
1891-92  ;  Instructor  in  Mathematics, 
Princeton  College,  1892-93;  Graduate 
Student,  University  of  Toronto,  1893-94  ; 
Lecturer  in  Mathematics  and  Pliysics, 
Toronto  Technical  School,  1894-95;  B.S., 
University  of  Toronto  (School  of  Practical 
Science),  1895. 

J.    PLAYFAIR    McMURRICH  : — 

B.  A.,  University  of  Toronto,  1879  ;  M.A., 
ibid.,  1882  ;  Assistant  in  Biological  Lab- 
oratory, ibid.,  1880-81 ;  Professor  of  Biol- 
ogy, Ontario  Agricultural  College,  1882-84 ; 
Instructor  in  Osteology,  Johns  Hopkins 
University,  1884-86;  Ph.D.,  Johns  Hop- 
kins University,  1885 ;  Professor  of  Biology, 
Haverford  College,  1886-89;  Docent  in 
Morphology,  Clark  University,  1889- 
91 ;  Assistant  Professor,  1891-92 ; 
Professor  of  Biology,  University  of  Cin- 
cinnati, 1892-94  ;  Professor  of  Anatomy, 
University  of  Michigan,  1894-. 

Author  of :  — 

On  the  Origin  of  the  So-called  Test-cells  in 
the  Ascidian  Ovum.  Studies  from 
Biol.  Lab.  J.  H.  U. ,  1882,  Vol.  2.  Ab- 
stract in  Biol.Centralblatt,  1882, Vol.  2; 
Arch,  de  Zool.  exp.  etgen.,  1882, Vol.  10. 

Note  on  the  Function  of  the  "  Test-cells  " 
in  Ascidian  Ova.  Zool.  Anzeiger,  1882, 
Vol.  5.  Abstract  in.  Jour.  Boy.  Micros. 
Soc,  1882,  Vol.  2, 

On  the  Osteology  and  Development  of 
Syngnathus  peckianus  (Storer). 
Quart.  Jour.  Micros.  Sci.,  1883,  Vol. 
23.     Abstract  in  J.  H.   TJ.   Circular, 

1883,  No.  27. 

The  Osteology  and  Myology  of  Amiurus 
catus  (L.)  Gill.  Proc.  of  the  Canadian 
Inst.,  Toronto,  1884,  Vol,  2.  Pre- 
liminary  Notice    in    Zool.    Anzeiger, 

1884,  Vol.  7. 

On  the  Structure  and  Affinities  of  Phytop- 
tus.  J.  H.  U.  Circular,  1884,  No.  35. 
Abstract  in  Jour.  Boy.  Micros.  Soc, 

1885,  Vol,  5. 


518 


Titles  of 


On  the  Tape-worm  Epizootic  among 
Lambs  (Taenia  expansa).  9th  Ann. 
Bep.  of  the  Ont.  Agricultural  College, 
Toronto,  1884, 

The  Cranial  Muscles  of  Amia  calva  (L.), 
with  a  consideration  of  the  Post-occipi- 
tal and  Hypoglossal  Nerves  in  the 
various  Vertebrate  Groups.  Studies 
from  Biol.  Lab.  J.  H.  U.,  1885,  Vol.  3. 
Preliminary  Notice  in  J.  H.  U.  Circu- 
lar, 1885,  No.  38. 

On  the  Existence  of  a  Post-oral  Band  of 
CUia  in  Gasteropod  Veligers.  J.  H.  U. 
Circular,  1885,  No.  43.  Abstract  in 
Jour.  Boy.  Micros.  Soc,  1886,  Vol. 
6. 

A  Contribution  to  the  Embryology  of 
the  Prosobranch  Gasteropods.  Studies 
from  Biol.  Lab.  J.  H.  U.,  1886,  Vol.  3. 
Preliminary  Notice  in  J.  H.  U.  Circular, 
1886,  No.  49.  Abstract  in  Jour.  Boy. 
Micros.  Soc,  1886,  Vol.  6. 

Notes  on  the  Actiniae  obtained  at  Beau- 
fort, N.  C.  Studies  from  Biol.  Lab. 
J.  H.  U.,  1887,  Vol.  4. 

On  the  Occurrence  of  an  Edwardsia  Stage 
in  the  Free-swimming  Embryos  of  a 
Hexactinian.  J.  H.  U.  Circular, 
1899,  No.  70.  Abstract  in  Jour.  Boy. 
Micros.  Soc,  1889,  Vol.  9. 

A  Contribution  to  the  Actinology  of  the 
Bermudas.  Proc.  of  the  Acad,  of  Nat. 
Sciences,  Philadelphia,  1889.  Abstract 
in  t/owr.  Boy.  Micros.  Soc,  1889,  Vol. 
9. 

Note  on  the  Structure  and  Systematic 
Position  of  Lebrunea  neglecta,  Duch. 
and  Mich.  Zool.  Anzeiger,  1880,  Vol. 
12.  Abstract  in  Jour.  Boy.  Micros. 
Soc,  1889,  Vol.  9. 

Article  "  Reproduction"  in  Buck's  Befer- 
ence  Handbook  of  the  Medical  Sciences, 

1889,  Vol.  8. 

The  Actiniaria  of  the  Bahama  Islands, 
W.  I.  Jour,  of  Morph.,  1889,  Vol.  3. 
Abstract  in  Jour.  Boy.  Micros.  Soc, 

1890,  Vol.  10 ;  American  Naturalist, 
1889 ;  Preliminary  Notice  in  J.  H.  U. 
Circular,  1889,  No.  70. 

Contributions  on  the  Morphology  of  the 
Actinozoa.     I.  The  Structure  of  Ceri- 


anthus  americanus.  Jour,  of  3forph., 
Oct.,  1890,  Vol.  4,  pp.  131-150. 

Contributions  on  the  Morphology  of  the 
Actinozoa.  II.  On  the  Development 
of  the  Hexactinise.  Ibid.,  Jan.,  1891, 
Vol.  4,  pp.  303-330. 

Contributions  on  the  Morphology  of  the 
Actinozoa.  III.  The  Phylogeny  of  the 
Actinozoa.  Ibid.,  June,  1891,  Vol.  5, 
pp. 125-164. 

The  Gastrgea  Theory  and  its  Successors. 
Biological  Lectures,  Marine  Biological 
Laboratory, Woods  Holl.  Ginn  &.  Co., 
Boston,  1891,  pp.  79-106. 

The  Formation  of  the  Germ-layers  in  the 
Isopod  Crustacea.  Zool.  Anzeiger, 
Jahrg.  15,  1892. 

Eeport  on  the  Actiniae  collected  by  the  U. 
S.  Fish  Commission  steamer  Albatross 
during  the  winter  of  1887-88.  Proc 
U.  S.  National  Museum,  1893,  Vol.  16, 
p.  119. 

A  Text-book  of  Invertebrate  Morphology. 
New  York,  1894. 

Embryology  of  the  Isopod  Crustacea. 
Jour,  of  Morph.,  May,  1895,  Vol.  11, 
pp.  63-154. 

Cell  Division  and  Development.  Biologi- 
cal Lectures,  Marine  Biological  Labora- 
tory, "Woods  Holl.  Ginn  &  Co. ,  Boston, 
1895,  pp.  125-147. 

Notes  on  Some  Actinians  from  the  Ba- 
hama Islands,  collected  by  the  late  Dr. 
J.  I.  Northrop.  Annals  N.  Y.  Acad, 
of  Science,  1896,  Vol.  9,  p.  181. 

The  Yolk-lobe  and  Centrosome  of  Fulgur 
carica.  Anat.  Anzeiger,  1896,  Bd.  12, 
p.  534. 

Contributions  on  the  Morphology  of  the 
Actinozoa.  IV.  On  Some  Irregulari- 
ties in  the  Number  of  the  Directive 
Mesenteries  in  the  Hexactinife.  Zool. 
Bulletin,  1897,  Vol.  1. 

The  Epithelium  of  the  So-called  Midgut 
of  the  Terrestrial  Isopods.  Jour,  of 
Morph.,  1897,  Vol.  14,  p.  83. 

A  Case  of  Crossed  Dystopia  of  the  Kid- 
ney with  Fusion.  Jour,  of  Anat.  and 
Phys.,  1898,  Vol.  32,  p.  652. 

Report  on  the  Actiniaria  collected  by  the 
Bahama  Expedition  of  the  State  Uni- 


Published  Papers. 


519 


versity  of  Iowa,  1893,     Bull.  Lab.  of 
Nat.  Hist.  State   Univ.  of  Iowa,  1898, 
Vol.  4,  p.  225. 
The  Present  Status  of  Anatomy.    Amer- 
ican Naturalist,  1899,  Vol.  33,  p.  185. 

FRANKLIN  P.  MALL:  — 

M.D.,  University  of  Michigan,  1883; 
University  of  Heidelberg,  1883-84; 
University  of  Leipzig,  1884-86  ;  Fellow, 
Instructor,  and  Associate  in  Pathology, 
Johns  Hopkins  University,  1886-89  ;  Ad- 
junct Professor  of  Vertebrate  Anat- 
omy, Clark  University,  1889-92  ;  Pro- 
fessor of  Anatomy,  University  of  Chicago, 
1892-93 ;  Professor  of  Anatomy,  Johns 
Hopkins  University,  1893-. 

Author  of :  — 

Entwickelung    der    Branchialbogen    und 

-Spalten    des    Hiihnchens.    Arch.    f. 

Anatomie    (His    u.     Braune),    1887, 

pp.  1-34,  3  pis. 
Die  Blut-  und  Lymphwege  im  Diinndarm 

des  Hundes.     Abhandl.  d.  K.  S.  Ge- 

sellsch.  der  Wissenschaften,  1887,  Vol. 

24,  pp.  153-189,  6  pis. 
The  First  Branchial  Arch  of  the  Chick, 

J.  H.   U.  Circular,  Feb.,  1888,   Vol. 

7,  p.  38. 
The  Branchial  Region  of  the  Dog,     Ibid., 

Feb.,  1888,  Vol.  7,  p.  39. 
Development  of   the    Eustachian    Tube, 

Middle  Ear,  Tympanic  Membrane,  and 

Meatus  of  the  Chick.     Studies  from 

Biol.  Lab.  J.  H.  U.,  June,  1888,  Vol. 

4,  pp.  185-192,  1  pi. 
The  Development  of  the  Branchial  Clefts 

of  the  Dog  with  Special  Reference  to 

the    Origin    of    the  Thymus    Gland. 

Ibid.,  pp.  193-216,  3  pis. 
Reticulated  and  Yellow  Elastic  Tissues. 

Anat.  Anzeiger,  June  1,  1888,  Vol.  3, 

pp.  397-401. 
Die  motorischen  Nerven  der  Portalvene, 

Du  Bois-Reymond's  Arch.f.  Physiolo- 

gie,  1890,  Supp.  Band,  pp.  57-58. 
Development   of    the    Lesser    Peritoneal 

Cavity  in  Birds  and  Mammals.     Jour. 

of  Morph.,   June,  1881,    Vol.   5,   pp. 

165-179. 


Das  Reticulirte  Gewebe.    Abhandl.  d.  K. 

S.  Gesellsch.  der  Wissenschaften,  1891, 

Vol.  17,  pp.  293-338,  11  pis. 
A  Human  Embryo  Twenty-six  Days  Old, 

Jour,  of  3Iorph.,  Dec,  1891,  Vol.   5, 

459-480,  2  pis. 
Methods  of  preserving  Human  Embryos. 

American  Naturalist,  Dec,  1891,  Vol. 

25,  pp.  1144-1146. 
Der  Einfluss  des  Systems  der  Vena  portae 

auf  die  Vertheilung  des  Blutes.     Du 

Bois-Beymond^s  Arch.  f.  Physiologie, 

1892,  pp,  409-453. 

The  Vessels  and  Walls  of  the  Dog's  Stom- 
ach. J.  H.  Hospital  Reports,  1896, 
Vol.  1,  pp.  1-36,  5  pis. 

A  Study  of  the  Intestinal  Contraction, 
Ibid.,  pp.  37-75,  3  pis. 

Healing  of  Intestinal  Sutures.  Ibid., 
pp.  76-92. 

Reversal  of  the  Intestine.  Ibid.,  pp.  93- 
110. 

A  Human  Embryo  of  the  Second  Week. 
Anat.  Anzeiger,  Aug.  5,  1893,  Vol.  8, 
pp.  630-633. 

Histogenesis  of  the  Retina  in  Amblystoma 
and  Necturus.    Jour,  of  Morph.,  May, 

1893,  Vol.  8,  pp,  415-432. 

Ccelom,  pp.  184-189  ;  Human  Embryos, 
pp.  268-269  ;  The  Heart,  pp.  391-395 ; 
Development  of  the  Thymus  Gland, 
pp.  875-877 ;  Development  of  the 
Thyroid  Gland,  pp.  879-882.  Ref. 
Handbook  of  Med.  Sciences  (Supp. 
Vol.). 

What  is  Biology  ?     Chaiitauquan,  Jan., 

1894,  Vol.  18,  pp.  411-414. 

Early  Human  Embryos  and  the  Mode  of 

their  Preservation.      Bull,   of  J.  H. 

Hospital,  Dec,  1893,  Vol,  4,  pp.  115- 

121. 
The  Preservation  of  Anatomical  Material 

for  Dissection.    Anat.  Anzeiger,  April 

9,  1896,  Vol.  11,  pp.  769-775. 
The  Contraction  of  the  Vena  Portse  and 

its  Influence  upon  the  Circulation.     J. 

H.  Hospital  Reports,  1896,  Vol.  1,  pp. 

111-156. 
Reticulated  Tissue  and  its  Relation  to  the 

Connective  Tissue  Fibrils.    Ibid. ,  1896, 

Vol,  1,  pp.  171-208,  9  pis. 


520 


Titles  of 


The  Anatomical  Course  and  Laboratory 

of    the     Johns    Hopkins    University. 

Bull,   of  J.  H.   Hospital,  May-June, 

1896,  Vol.  7,  pp.  85-100,  5  pis. 
Development    of    the    Human     Coslom. 

Jour,  of  Morph.,  Feb.,  1897,  Vol.  12, 

pp.  395^53. 
Ueber  die  Entwickelung  des  menschlichen 

Darmes  und  seiner  Lage  beim  Erwach- 

senen.    His.'' s  Arch.  f.  Anatomie,  1897, 

Supp.  Band,  pp.  403-434,  10  pis. 
Development  of  the  Ventral  Abdominal 

Walls  in  Man.    Jour,  of  Morph. ,  June, 

1898,  Vol.  14,  pp.  347-366,  6  pis. 
Development  of  the  Human  Intestine  and 

its  Position  in  the  Adult.     Bull,  of 

J.  H  Hospital,  Sept.-Oct.,  1898,  Vol. 

9,  pp.  197-208,  5  pis. 
The   Lobule  of   the   Spleen.     Ibid.,  pp. 

218-219. 
Development  of  the  Internal  Mammary 

and  Deep  Epigastric  Arteries  in  Man. 

lUd.,  pp.  232-235. 
The  Value  of  Embryological  Specimens. 

Md.   Med.  Jour.,  Oct.  29,  1898,  Vol. 

40,  p.  29. 
Liberty  in  Medical    Education.      Phila. 

Med.  Jour.,  April  1,  1899,  Vol.  3,  p. 

720. 

CHARLES  W.    MARSH:  — 

Ph.B.,  Columbia  College,  School  of 
Mines,  1879;  Ph.D.,  Columbia  College, 
1882 ;  Assistant  in  Chemistry,  Green 
School  of  Science,  Princeton,  N.  J.,  1882- 
85  ;  University  of  Berlin,  1885-87;  Assist- 
ant in  Chemistry,  Lehigh  University, 
1887-89  ;  Honorary  Fellow  in  Chemis- 
try, Clark  University,  1889-90  ;  Elec- 
trical Engineer,  New  York  City,  1893-. 

Author  of :  — 

Note  on  the  Ammonia-Process  for  "Water 
Analysis.  Am.  Chem.  Jour.,  July, 
1882,  Vol.  4,  pp.  188-192. 

A  Method  for  the  Detection  of  Chlorine, 
Bromine,  Iodine,  and  Sulphur  in  Or- 
ganic Compounds.  Ibid.,  April,  1889, 
Vol.  11,  pp.  240-244. 

A  New  Form  of  Adapter.  Am.  Jour,  of 
Anal.  Chem.,  Jan.,  1889. 


The  Reduction  of  Barium  Sulphate  to 
Barium  Sulphide  on  Ignition  with 
Filter  Paper.     Ibid.,  April,  1889. 

ALFRED    G.    MAYER:  — 

M.E.,  Stevens  Institute,  Hoboken,  N.  J., 
188!) ;  Assistant  in  Physics,  Clark  Uni- 
versity, 1889-90  ;  Assistant  in  Physics, 
University  of  Kansas,  1890-92  ;  Graduate 
Student  in  Zoology,  Harvard  University, 
1892-95  ;  Museum  Assistant  in  Charge  of 
Radiates,  Echinoderms,  and  Polype,  and 
Assistant  to  Dr.  Alexander  Agassiz, 
1895- ;  Sc.D.,  Harvard  University,  1896; 
Member  of :  American  Society  of  Natu- 
ralists, American  Morphological  Society, 
Boston  Society  of  Natural  History,  Ameri- 
can Association  for  Advancement  of  Sci- 
ence ;  President  of  the  Cambridge  Ento- 
mological Society. 

Author  of  :  — 

Radiation  and   Absorption  of   Heat  by 

Leaves.     Am.    Jour,    of   Sci.,   April, 

1893,  Vol.  45,  pp.  340-346. 
Some  New  Medusfe  from  the  Bahamas. 

Bull.  Mus.  Comp.  Zool,  1894,  Vol.  25, 

pp.  23.5-242,  3  pis. 
Color  and  Color-Patterns  of  Moths  and 

Butterflies.     Ibid.,  1897,  Vol.  30,  pp. 

169-256,  10  pis. 
The  Development  of  Wing  Scales  and  their 

Pigment    in    Butterflies    and    Moths. 

Ibid.,  1896,  Vol.  29,  pp.  209-236,  7  pis. 
A  New  Hypothesis  of   Seasonal  Dimor- 
phism in  Lepidoptera.     Psyche,  April- 
May,  1897,  Vol.  8,  pp.  47-50,  59-62. 
On  Dactylometra.     (With  A.  Agassiz.) 

Bull.  Mus.  Comp.  Zool.,  1898,  Vol.  32, 

pp.  1-11,  13  pis. 
On  Some  Medusse  from  Australia.    (With 

A.  Agassiz.)     Ibid.,  1898,  Vol.  32,  pp. 

12-19,  3  pis. 
Acalephs  from  the  Fiji  Islands.     (With 

A.  Agassiz.)     Ibid.,  1899,  Vol.  32,  pp. 

151-189,  17  pis. 
On  an  Atlantic  "Palolo"  Worm.     Ibid. 

(In  press.) 
Medusse  of  the  Atlantic  Coast  of  North 

America.     (With  A.  Agassiz.)     Mem. 

Mus.  Comp.  Zool. 


Published  Papers. 


521 


A.    D.    MEAD:  — 

A.B.,  Middlebury  College,  1890;  A.  M., 
Brown  University,  1891  ;  Fellow  in  Mor- 
phology, Clark  University,  1891-92  ; 

Fellow  in  Biology,  University  of  Chicago, 
1892-95;  Pli.D.,  University  of  Chicago, 
1895 ;  Instructor  in  Comparative  Anatomy, 
Brown  University,  1895-96 ;  Associate 
Professor  of  Embryology  and  Neurology, 
ibid.,  1897-. 

Author  of :  — 

Preliminary  Account  of  the  Cell-Lineage 
of  Amphitrite  and  other  Annelids. 
Jour,  of  3Iorph.,  Sept.,  1894,  Vol.  9, 
pp.  465-473. 

Some  Observations  on  Maturation  and 
Fecundation  of  Chsetopterus  perga- 
mentaceus  Cuvier.  Ibid.,  Jan.,  1895, 
Vol.  10,  pp.  313-317. 

The  Origin  of  the  Egg  Centrosomes. 
Ibid.,  Feb.,  1897,  Vol.  12,  pp.  391-394. 

The  Early  Development  of  Marine  Anne- 
lids. (Thesis.)  /6id.,  May,  1897,  Vol. 
13,  pp.  227-326. 

The  Origin  and  Behavior  of  the  Centro- 
somes in  the  Annelid  Egg.  Ibid., 
June,  1898,  Vol.  14,  pp.  181-218,  4  pis. 

The  Rate  of  Cell  Division  and  the  Function 
of  the  Centrosome.  Woods  Hall  Biol. 
Lectures,  1896-97.  Ginn  &  Co.,  Bos- 
ton, 1898,  pp.  20.3-218. 

The  Breeding  of  Animals  at  "Woods  Holl 
during  the  Month  of  April,  1898. 
Science,  May  20,  1898,  N,  S.,  Vol.  7, 
pp.  702-704. 

Habits  and  Life  History  of  the  Starfish.  I. 
SSth  Rep.  of  the  Com.  of  Inland  Fish- 
eries of  B.  I.,  1898. 

Habits  and  Life  History  of  the  Starfish. 
IL    S9thBep.,  ibid.,  1899. 

Peridinium  and  the  "Red  Water"  in 
Narragansett  Bay.  Science,  Nov  18, 
1898,  N.  S.,  Vol.  8,  pp.  707-709. 

The  Cell  Origin  of  the  Prototroch.  Woods 
Holl  Biol.  Lectures,  1898. 

GEORGE  P.  METZLER:  — 

A.B.,  Albert  College,  Ontario,  Can., 
1880;  Head  Master,  Port  Dover  High 
School,    1880-81;    Professor    of    Mathe- 


matics, Albert  College,  1881-84;  A.M., 
Victoria  College,  1883  ;  Professor  of 
Mathematics,  Marietta  College,  1889-90  ; 
Ph.D.,  Johns  Hopkins  University,  1891  ; 
Honorary  Fellow  in  Psychology, 
Clark  University,  1891-92  ;  Docent  in 
University  of  Chicago  and  Instructor  in 
Mathematics,  University  of  Michigan, 
1892-93  ;  University  of  Gottingen,  1893- 
94 ;  University  of  Berlin,  1894-95  ;  Asso- 
ciate in  Mathematics,  Queens  College, 
1896-97  ;  Assistant  Pastor  Methodist 
Church,  Newburgh,  Can.,  1897-98  ;  Pas- 
tor of  Methodist  Church,  Wilberforce, 
Canada,  1898-. 

Author  of:  — 

Equations  and  Variables  Associated  with 
the  Linear  Differential  Equation.  An- 
nals of  Math.,  Vol.  9,  pp.  171-178  ; 
Vol.  11,  pp.  1-9. 

Surfaces  of  Rotation  with  Constant  Meas- 
ure of  Curvature  and  their  Represen- 
tation on  the  Hyperbolic  (Cayley's) 
Plane.  Am.  Jour,  of  Math.,  Jan. , : 
Vol.  20,  pp.  76-86. 

WILLIAM  H.  METZLER:  — 

A.B.,  University  of  Toronto, 
Science  Master,  Collegiate  Institute,  Inger- 
soll,  Ont.,  1888-89 ;  Fellow  in  Mathe- 
matics, Clark  University,  1889-92; 
Ph.D.,  Clark  University,  1893;  In- 
structor in  Mathematics,  Massachusetts 
Institute  of  Technology,  1892-94  ;  Pro- 
fessor of  Mathematics,  Genesee  Wesleyan 
Academy,  1894-95 ;  Associate  Professor 
of  Mathematics,  Syracuse  University, 
1895-96  ;  Professor  of  Mathematics,  ibid., 
1896- ;  Member  of :  American  Association 
for  the  Advancement  of  Science  ;  Ameri- 
can Mathematical  Society ;  Deutsche 
Mathematilier-Vereinigung ;  Mathemat- 
ical Association  (England)  ;  British  As- 
sociation for  the  Advancement  of  Science  ; 
London  Mathematical  Society. 

Author  of :  — 

On  the  Roots  of  Matrices.  Am.  Jour,  of 
3Iath.,  Oct.,  1892,  Vol.  14,  pp.  326- 
377. 


522 


Titles  of 


On  Certain  Properties  of  Symmetric,  Skew 
Symmetric,  and  Orthogonal  Matrices. 
Ihid.,  July,  1893,  Vol.  15,  pp.  274-282. 

Homogeneous  Strains.  Annals  of  Math., 
Vol.  8,  No.  5. 

On  Compound  Determinants.  Am.  Jour, 
of  Math.,  April,  1894,  Vol.  16,  pp. 
131-150. 

Matrices  which  Represent  Vectors.  Tech- 
nology Quarterly,  Vol.  6.  No.  4. 

Some  Notes  on  Symmetric  Functions. 
Proc.  London  Math.   Soc,  March  11, 

1897,  Vol.  28,  pp.  390-393. 
Compound  Determinants.     Am.  Jour,  of 

Math.,  July,  1898,  Vol.  20,  pp.  253- 
272. 
A  Theorem  in  Determinants.     Ibid. ,  July, 

1898,  Vol.  20,  pp.  273-276. 

On  the  Excess  of  the  Number  of  Combina- 
tions in  a  set  which  have  an  even 
number  of  inversions  over  those  which 
have  an  odd  number.     (In  press.) 

On  the  Roots  of  a  Determinantal  Equa- 
tion. Am.  Jour,  of  Math.,  Oct.,  1899, 
Vol.  21,  pp.  367-368. 

On  a  Determinant  each  of  whose  Elements 
is  the  Product  of  K  Factors.  (In 
press.) 

On  a  Theorem  in  Determinants  related  to 
Laplace's.     (In  press.) 

ADOLF   MEYER  :  —  ' 

Maturitatsexamen,  Gymnasium,  Ziirich, 
1885 ;  Medical  Staatsexamen,  Zurich, 
1890;  Graduate  Student  in  Medicine, 
Paris,  Edinburgh,  and  London,  1890-91 ; 
Neurological  Work  in  the  Laboratory  of 
the  Clinic  of  Psychiatry  of  Professor  A. 
Forel,  Zurich,  1891  ;  Neurological  Student, 
Vienna,  1892  ;  M.D.,  University  of  Zurich, 
1892  ;  Decent  in  Neurology,  University  of 
Chicago,  and  Pathologist,  Illinois  Hospital 
for  the  Insane,  1893-95  ;  Director  of  the 
clinical  and  laboratory  work,  Worcester 
Insane  Hospital,  1895-  ;  Docent  in  Psy- 
chiatry, Clark  University,  1895-. 

Author   of :  — 

Medicinische  Studien  in  Paris,  Edinburgh, 
und  London.  Correspondenz-Blatt 
fur   Schweizer  Aerzte,   June  1,  1891, 


Vol.  21,  pp.  350-357  ;  June  15,  pp. 
381-386  ;  July  1,  pp.  417-420. 

Ueber  das  Vorderhirn  eiuiger  Reptilien. 
Zeitschrift  fur  wissenschaftliche  Zo- 
ologie,  1892,  Vol.  55,  pp.  63-133,  2 
pis. 

Zur  Homologie  der  Fornixcommissur  und 
des  Septum  lucidum  bei  den  Reptilien 
und  Saugern.  Anatomischer Anzeiger, 
March  15,  1895,  Vol.  10,  pp.  474-482. 

Neurological  Work  at  Zurich.  Journal  of 
Comparative  Neurology,  1893,  Vol.  3, 
pp.  1-6,  41-44,  114-118. 

How  Can  We  Prepare  Neurological  Ma- 
terial to  the  Best  Advantage  ?  Jour- 
nal of  Nervous  and  Mental  Diseases, 
May,  1894,  Vol.  19,  pp.  277-291. 

Considerations  on  the  Findings  in  the 
Spinal  Cord  of  Three  General  Para- 
lytics. Am.  Jour,  of  Insanity,  Jan., 
1895,  Vol.  51,  pp.  374-379. 

Mental  Abnormalities  in  Children  during 
Primary  Education.  Tran.  III.  Soc. 
for  Child  Study,  Dec,  1894,  Vol.  1, 
No.  1,  pp.  48-58. 

Schedule  for  the  Study  of  Mental  Abnor- 
malities in  Children.  Ibid.,  May, 
1895,  Vol.  1,  No.  2,  pp.  53-57. 

On  the  Observation  of  Abnormalities  of 
Children.  Child  Study  Monthly,  May, 
1895,  Vol.  1,  pp.  1-12. 

Report  to  the  Governor  of  Illinois  on  the 
Treatment  of  the  Insane.  Compila- 
tion of  Special  Beports,  etc.,  Spring- 
field, 111.,  1894,  pp.  18-29. 

A  Few  Demonstrations  of  Pathology  of 
the  Brain  and  Remarks  on  the  Prob- 
lems connected  with  Them.  Am. 
Jour,  of  Insanity,  Oct.,  1895,  Vol.  52, 
pp.  243-249,  3  pis. 

On  the  Diseases  of  Women  as  a  Cause  of 
Insanity  in  the  Light  of  Observations 
in  Sixty-nine  Autopsies.  Tran.  of  the 
III.  State  Med.  Soc,  1895. 

A  Review  of  the  Signs  of  Degeneration 
and  of  Methods  of  Registration.  Ain. 
Jour,  of  Insanity,  Jan.,  1896,  Vol.  52, 
pp.  344-363. 

Pathological  Report  of  the  Illinois  Eastern 
Hospital  for  the  Insane  at  Kankakee, 
111.     Chicago,  1896,  pp.  1-236,  16  pis. 


Published  Paj)ers. 


523 


A  Case  of  Landry's  Paralysis,  with  Au- 
topsy. (With  Dr.  Th.  Diller.)  Am. 
Jour,  of  the  Medical  Sciences,  April, 

1896,  Vol.  115,  pp.  404^13. 
Etiological,     Clinical,    and    Pathological 

Factors  in  Diagnosis  and  Rational 
Classification  of  Infectious,  Toxic,  and 
Asthenic  Diseases  of  the  Peripheral 
Nerves,  Spinal  Cord,  and  Brain.  3Iecli- 
cine,  Detroit,  Mich.,  Aug.  1896,  Vol.  2, 
pp.  6.39-652. 
A  Short  Sketch  of  the  Problems  of  Psy- 
chiatry.   A7n.  Jour,  of  Insanity,  April, 

1897,  Vol.  53,  pp.  538-549. 

General  Paralysis  and  Other  Nervous  and 
Mental  Affections  Following  Syphilitic 
Infection.  Yale  Medical  Journal, 
May,  1897,  Vol.  3,  pp.  311-317. 

Demonstration  of  Various  Tjrpes  of 
Changes  in  the  Giant  Cells  of  the 
Paracentral  Lobule.  Am.  Jour,  of 
Insanity,  Oct.  1897,  Vol.  64,  pp.  221- 
226,  3  pis. 

Anatomical  Findings  in  a  Case  of  Facial 
Paralysis  of  Ten  Days'  Duration  in  a 
General  Paralytic,  with  Remarks  on 
the  Termination  of  the  "Auditory" 
Nerves.  Jour,  of  Experimental  Medi- 
cine, Nov.  1897,  Vol.  2,  pp.  607-610, 
2  pis. 

Special  Report  of  the  Medical  Depart- 
ment of  the  Worcester  Lunatic  Hos- 
pital. Annual  Report,  Oct.  1898,  pp. 
20-27. 

Critical  Review  of  the  Data  and  General 
Methods  and  Deductions  of  Modern 
Neurology.  Jour,  of  Comp.  Neurol- 
ogy, Nov.-Dec,  1898,  Vol.  8,  pp.  11.3- 
148  ;  249-313,  7  pis. 

Critical  Review  of  Recent  Publications  of 
Bethe  and  Nissl.  Ihid.,  March,  1899, 
Vol.  9,  pp.  38-45. 

Reviews  in  the  Neurologisches  Central- 
blatt,  Psychological  Bevieio,  Am,  Jour. 
of  Insanity,  Jour,  of  Nervous  andMen- 
tal  Disease. 

ARTHUR  MICHAEL:  — 

University  of  Heidelberg,  1873-75  ;  Uni- 
versity of  Berlin,  1875-78  ;  :fecole  de  M^de- 
cine,  1879-80 ;   Professor   of   Chemistry, 


Tufts  College,  1881-89  ;  Ph.D.  (Honor- 
ary), Tufts  College,  1889;  Professor  of 
Chemistry,  Clark  University,  Sept.- 
Dec. ,  1889  ;  Research  Work  in  England, 
1890-94  ;  Professor  of  Chemistry,  Tufts 
College,  1894-. 

Author  of:  — 

Ueber  die  Einwirkung  von  Kaliumsulfhy- 

drat  auf  Chloralhydrat.    Ber.  d.  deuts. 

chem.   Gesellschaft,  1876,  Vol.  9,   pp. 

1267-1268. 
Ueber  die  Darstellung  und  Eigenschaften 

des    Trijodresorcins.       (With    T.    H. 

Norton.)    Ibid.,  Vol.  9,  pp.  1752-1753. 
Ueber  die  Einwirkung  von  wasserentzie- 

henden  Mitteln  auf  Saureanhydride. 

(With  S.  Gabriel.)     Ibid.,  1877,  Vol. 

10,     pp.    391-393;    1551-1562,    2199- 

2210;   1878,   Vol.   11,   pp.   1007-1021, 

1679-1683. 
Zur  Darstellung  der  Paramidobenzoesaure. 

Ibid.,  1877,  Vol.  10,  pp.  576-580. 
Ueber  die  Diamidosulfobenzid-Dicarbon- 

saure.     (With  T.  H.  Norton.)    Ibid., 

Vol.  10,  pp.  580-583. 
Zur  Kenntniss  der  aromatischen  Sulfone. 

(With  A.  Adair.)     Ibid.,  Vol.  10,  pp. 

583-587. 
Ueber  die    Einwirkung    des    Broms  auf 

Aethylphtalimid.     Ibid.  Vol.  10,   pp. 

1644-1645. 
Ueber  die  Einwirkung  des  Chlorjods  auf 

aromatische    Amine.      (With    L.    M. 

Norton.)      Ibid.,   1878,   Vol.   11,   pp. 

107-116. 
Zm-  Kenntniss  der  aromatischen  Sulfone. 

(With  A.  Adair.)     Ibid.,  Vol.  11,  pp. 

116-121. 
Ueber  Benzylmethylglycolsaure.      (With 

S.  Gabriel.)     Ibid.,  1879,  Vol.  12,  pp. 

814-816. 
On  the   Action  of   Iodine  Monochloride 

iipon  Aromatic  Acids.     (With  L.  M. 

Norton.)      Ain.    Chem.   Jour.,    1879, 

Vol.  1,  pp.  255-267. 
On  the  Synthesis  of  Helicin  and  Phenol- 

glucoside.     Ibid.,  Vol.  1,  pp.  305-312. 
On  a  New  Formation  of  Stilbene  and  some 

of  its  Derivatives.     Ibid.,  Vol.  1,  pp. 

312-316. 


524 


Titles  of 


On  Mono-Ethylphthalate.  Ibid.,  1880, 
Vol.  1,  pp.  413-416. 

On  a  New  Formation  of  Ethyl-Mustard 
Oil.     Ibid.,  Vol.  1,  pp.  41G-418. 

On  the  Preparation  of  Methyl  Aldehyde. 
Ibid.,  Vol.  1,  pp.  418-420. 

On  the  ' '  Migration  of  Atoms  in  the  Mole- 
cule" and  Reimer's  Chloroform  Alde- 
hyde Reaction.  Ibid.,  Vol.  1,  pp. 
420-426. 

On  a-  and  fc-Monobromcrotonic  Acids. 
(WithL.  M.  Norton.)  Ibid.,  Vol.  2, 
pp.  11-19. 

Preliminary  Note  on  the  Synthesis  of 
Methylconine  and  Constitution  of  Co- 
nine. (With  Charles  Gundelach.) 
Ibid.,  Vol.  2,  pp.  171-172. 

Ueber  die  Einwirkung  von  aromatischen 
Oxysjiuren  auf  Phenole.  Ber.  d. 
deuts.  chem.  Gesellschaft,  1881,  Vol. 
14,  pp.  656-658. 

Ueber  die  Synthese  des  Methylarbutins. 
Ibid.   Vol.  14,  pp.  2097-2102. 

Zur  Kenntniss  des  Paraconiins.  Ibid., 
Vol.  14,  pp.  2105-2110. 

Ueber  die  Synthese  des  Salcins  und  des 
Anhydrosalicylglucosids.  Ibid.,  1882, 
Vol.  15,  pp.  1922-1925. 

On  the  Action  of  Aromatic  Oxy-acids  on 
Phenols.  Am.  Chem.  Jour.,  1883, 
Vol.  5,  pp.  81-97. 

On  Some  Properties  of  Phenylsulphona- 
cetic  Ethers.  (With  A.  M.  Comey.) 
Ibid.,  Vol.  5,  pp.  116-119. 

Synthetical  Researches  in  the  Glucoside 
Group.     Ibid.,  Vol.  5,  pp.  171-182. 

On  the  Formation  of  Crotonic  and  6-Oxy- 
butric  Aldehydes  from  Ethyl  Alde- 
hyde. (With  Adolph  Kopp.)  Ibid., 
Vol.  5,  pp.  182-191. 

On  the  Action  of  Sodium  Ethyl  Oxide  on 
Bromethylidenebromide.  Ibid.,  Vol. 
5,  pp.  192-197. 

A  New  Synthesis  of  Allantoin  and  Some 
Suggestions  on  the  Constitution  of 
Uric  Acid.  Ibid.,  Vol.  5,  pp.  198- 
202. 

On  a  Convenient  Method  for  Preparing 
Bromacetic  Acid.  Ibid.,  Vol.  5,  pp. 
202-203. 

On  Several  Cases  of  Intermolecular  Re- 


arrangement.    Ibid. ,  Vol.  5,  pp.  203- 

205. 
On  a  New  Synthesis  of  Cinnamic  Acid. 

Ibid.,  Vol.  5,  pp.  205-206. 
On  the  Action  of  Aldehydes  on  Phenols. 

Ibid.,  Vol.  5,  pp.  339-349. 
Action  of  Ethylaldehyde   on   Orcin  and 

Resorcin.       (With    A.    M.    Comey.) 

Ibid.,  Vol.  5,  pp.  349-353. 
Some  Convenient    Quantitative    Lecture 

Apparatus.      Ibid.,  Vol.    5,  pp.  353- 

359. 
Observations  on  the  Action   of  Acetyl- 

chloride    and    Acetic    Anhydride    on 

Corn  and  Wheat  Starch.     Ibid.,  Vol. 

5,  pp.  359-360. 
On  the  Constitution  of  Resocyanin.    Ibid., 

Vol.  5,  pp.  434-440. 
Ueber  die  optisch-inactive  Asparaginsaure. 

(With    J.   F.  Wing.)     Ber.  d.  deuts. 

chem.  Gesellschaft,   1884,  Vol.  17,  p. 

2984. 
On  the  Action  of  Sodium  Phenylsulphin- 

ate  on  Methylene  Iodide.     (With  G. 

M.  Palmer.)     Am.  Chem.  Jour.,  1884, 

Vol.  6,  pp.  253-257. 
On  the  Conversion  of  Organic  Isocyanates 

into    Mustard    Oils.      (With    G.    M. 

Palmer.)     Ibid.,  Vol.  6,  pp.  257-260. 
Synthetical  Researches  in  the  Glucoside 

Group.     Ibid.,  Vol.  6,  pp.  336-340. 
On  the  Action  of  Methyl  Iodide  on  As- 

paragine.     (With  J.  F.  Wing.)     Ibid., 

1885,  Vol.  6,  pp.  419-422. 
On  Some  Properties  of  Phenylsulphona- 

cetic  Ethers.      (With  G.  M.  Palmer.) 

Ibid.,  Vol.  7,  pp.  65-71. 
Note  on  the  Constitution  of  the  Addition- 
Product  of  Chlorhydric  Acid  to  Ethyl- 
cyanide.      (With  J.  F.  Wing.)     Ibid., 

Vol.  7,  pp.  71-74. 
On  the  Decomposition  of  Cinchonine  by 

Sodium  Ethylate.     Ibid.,  Vol.  7,  pp. 

182-189. 
On   Simultaneous  Oxidation  and  Reduc- 
tion by  Means  of  Hydrocyanic  Acid. 

(With  G.  M.  Palmer.)     Ibid.,  Vol.  7, 

pp.  189-194. 
On  the  Action  of  Alkyl  Iodides  on  Amido 

Acids.     (With   J.   F.    Wing.)     Ibid., 

Vol.  7,  pp.  195-199. 


Published  Paj^ers. 


525 


On  Eesacetophenone.  (With  G.  M. 
Palmer.)     Ihid.,  Vol.  7,  pp.  275-277. 

On  Inactive  Aspartic  Acid.  (With  J.  F. 
Wing.)     Ibid.,  Vol.  7.  pp.  278-281. 

Ueber  die  Einwirkung  von  FUnffach- 
Chlorphosphor  auf  die  Aether  organ- 
ischer  Sauren.  Ber.  d.  deuts.  chem. 
Gesellschaft,  1886,  Vol.  19,  pp.  84.5- 
847. 

Ueber  einen  Zusammenhang  zwischen 
Anilidbildung  und  der  Constitution 
ungesattigter,  mehrbasischer,  organ- 
ischer  Sauren.  Ibid.,  Vol.  19,  pp. 
1372-1375. 

Ueber  einen  Zusammenhang  zwischen 
Anilidbildung  und  der  Constitution 
ungesattigter,  mehrbasischer,  organ- 
ischer  Sauren.  (With  G.  M.  Palmer.) 
Ibid.,  Vol.  19,  pp.  1375-1376. 

Ueber  die  Einwirkung  des  Anilins  auf  die 
Brommalein  und  Chlorfumarsaure. 
Ibid.,  Vol.  19,  pp.  1377-1378. 

Zur  Isomeric  in  der  Zimmtsaurereihe. 
(With  G.  M.  Browne.)  Ibid.,  Vol. 
19,  pp.  1378-1381. 

Zur  Isomeric  in  der  Fettreihe.  Ibid., 
Vol.  19,  pp.  1381-1386. 

Ueber  die  Nitrirung  des  Phenylhydrazins. 
Ibid.,  Vol.  19,  pp.  1368-1388. 

Zur  Kenntniss  der  Einwirkung  von  Alde- 
hyden  auf  Phenole.  (With  J.  P.  Ry- 
der.)    Ibid.,  Vol.  19,  pp.  1388-1390. 

Die  Citraconsaure  als  Reagenz  zur  Erken- 
nung  und  Scheidung  der  aromatischen 
Amine.     Ibid.,  Vol.  19,  pp.  1390-1392. 

Ueberfiihrung  der  a-Bromzimmtather  in 
Benzoylessigather.  (With  G.  M. 
Browne.)  Ibid.,  Vol.  19,  pp.  1392- 
1393. 

Zur  Isomeric  in  der  Zimmtsaurereihe. 
(With  G.  M.  Browne.)  Ibid.,  1887, 
Vol.  20,  pp.  550-556. 

Bemerkungen  zu  einer  Abhandlung  des 
Hrn.  L.  Claisen.  Ibid.,  Vol.  20,  pp. 
1572-1573. 

On  the  Addition  of  Sodium  Acetacetic 
Ether  and  Analogous  Sodium  Com- 
pounds to  Unsaturated  Organic  Ethers. 
Am.  Chem.  Jour.,  1887,  Vol.  9,  pp. 
112-124. 

On    Some  New  Reactions  with  Sodium 


Acetacetic  and  Sodium  Malonic  Ethers. 

Ibid.,  Vol.  9,  pp.  124-129. 
On  the  Action  of  Aldehydes  on  Phenols. 

(With  J.  P.    Ryder.)     Ibid.,  Vol.  9, 

pp.  130-137. 
Researches  on  Alloisomerism.    Ibid.,  Vol. 

9,  pp.  180-183. 
A  Relation  between  the  Constitution  of 

Polybasic  Unsaturated  Organic  Acids 

and  the  Formation  of  their  Anilides. 

Ibid.,  Vol.  9,  pp.  183-197. 
A  Relation  between  the  Constitution  of 

Polybasic  Unsaturated  Organic  Acids 

and  the  Formation  of  their  Anilides. 

(With  G.  M.  Palmer.)     Ibid.,  Vol.  9, 

pp.  197-204. 
On  the  Action  of  Phosphorus  Pentachlo- 

ride  on  the  Ethers  of  Organic  Acids, 

and    on    some  Derivatives  of  Acetic 

Acid.     Ibid.,  Vol.  9,  pp.  205-217. 
On  the  Action  of  Phosphorus  Pentachlo- 

ride  on  Acetanilide.    Ibid.,  Vol.  9,  pp. 

217-219. 
Preliminary  Notes.     Ibid.,   Vol.    9,    pp. 

219-222. 
Researches  on  Alloisomerism.     (With  G. 

M.  Browne.)     Ibid.,  Vol.  9,  pp.  274- 

289. 
Remarks  on  the  Constitution  of  Levulinic 

and  Maleic  Acids.     Ibid.,  Vol.  9,  pp. 

364-372. 
Ueber  eine  bequeme  Darstellungsweise  von 

bromirten  Fettsauren.    Jou7:  f.  prak- 

tische  Chemie,  1887,  Vol.  35,  pp.  92-95. 
Das  Verhalten  von  Essigsaure  und  einigen 

Derivaten  derselben  gegen  Fiinffach- 

Chlorphosphor.     Ibid.,    Vol.    35,    pp. 

95-96. 
Ueber  die  Constitution  der  Trimethylen- 

tricarbonsaure.     Ibid.,    Vol.    35,    pp. 

132-136. 
Zur  Kenntniss  der  Einwirkung  des  Fiinf- 

fach-Chlorphosphors    auf    Acetanilid. 

Ibid., Vol.  35,  pp.  207-208. 
Ueber   die    Bildung    des    Indigblau   aus 

Orthonitrophenylpropiolsaure    mittelst 

Cyankalium.     Ibid.,  Vol.  35,  pp.  254- 

256. 
Ueber  Alloisomerie  in  der  Crotonsaure- 

reihe.     (With  G.  M.  Browne.)     Ibid., 

Vol.  35,  pp.  257-259. 


526 


Titles  of 


Ueber  die  Addition  von  Natriumacetessig- 
und  Natriummalonsaureatliern  zu  den 
Aethern  ungesattigter  Sauren.     Ibid., 
Vol.  35,  pp.  349-356. 
Die  Reduction  von  Alpha-  und  AUoalpha- 
bromzimmtsauren      zn      Ziinmtsaure. 
Ihid.,  Vol.  35,  pp.  357-358. 
Ueber  aromatische  Hydroxylamine.  ("With 
G.  M.  Browne.)     Ibid.,   Vol.   35,  pp. 
358-359. 
Ueber  neue  Reactionen  mit  Natriumacet- 
essig-    und    Natriummalonsaureather. 
Ibid.,  Vol.  35,  pp.  449-459. 
Ueber  das  Verhalten  von  Oxalsaureather 
zu  Resorcin.     Ibid.,  Vol.  35,  pp.  510- 
512. 
Antwort   auf    eine    Bemerkung    von    L. 

Claisen.     Ibid.,  Vol.  36,  pp.  113-114. 
Zur    Isomerie    in   der    Crotonsaurereihe. 
(With  G.  M.  Browne. )     Ibid. ,  Vol.  36, 
pp.  174-176. 
Zur  Constitution    des    Natriumacetessig- 
athers.     Ibid.,  1888,  Vol.  37,  pp.  473- 
530. 
Ueber  das  Verhalten  von  Natriummalon- 
ather  gegen  Resorcinol.    Ibid.,  Vol.  37, 
pp.  469-471. 
Zur  Alloisomerie  in  der  Crotonsaurereihe. 
(With  H.  Pendleton.)     Ibid.,  Vol.  38, 
pp.  1-5. 
Zur    Kritik    der    Abhandlung     von    J, 
Wislicenus :     ' '  Ueber    die    raumliche 
Anordnung  der  Atome  in  organischen 
Molekulen."     Ibid.,  Vol.  38,  pp.  6-39. 
Preliminary  Note  on  the  Constitution  of 
Sodium  Acetacetic  and  Malonic  Ethers. 
Am.   Chem.  Jour.,  1888,  Vol.  10,  pp. 
158-160. 
Bemerkung  zu  der  Abhandlung  von  Otto 
und  Rossing  liber  die  Ersetzbarkeit  des 
Natriums  im  Natriumphenylsulfones- 
sigather  durch  Alkyle.     Ber.  d.  deuts. 
chem.   Gesellschaft,  1890,  Vol.  23,  pp. 
669-671. 
On  the  Constitution  of  Sodium  Acetacetic 
Ether.     Am.  Chem.  Jour.,  1892,  Vol. 
14,  pp.  481-544. 
On  the  Action  of  Acetic  Anhydride  on 
Phenylpropiolic    Acid.     (With    J.  E. 
Bucher.)     Ibid.,  1898,  Vol  20,  pp.  89- 
120. 


On  the  Formation  of  Imido-1,  2-Diazo. 
Derivatives  from  Aromatic  Azimides 
and    Esters    of    Acetylenecarboxylic 

Acids.     (With   F.   Luehn   and   H.  H, 
Higbee.)      Ibid.,   Vol.    20,    pp.    377- 
395. 
Zur  Schmelzpunktsbestimmung  von  hoch- 
schmelzenden  und  sogen.  unschmelz- 

baren  organischen  Verbinduugen.    Ber. 

d.    deuts.    chem.    Gesellschaft,     1895, 

Vol.  28,  pp.  1629-1633. 
Ueber  die  Addition  von  Schwefel  zu  un- 

gesattigten  organischen  Verbindungen. 

Ibid.,  Vol.  28,  pp.  1633-1637. 
Ueber  die  Einwirkung  von  Essigsaurean- 

hydrid  auf  Sauren  der  Acetylenreihel. 

(With  J.  E.  Bucher.)     Ibid.,  Vol.  28, 

pp. 2511-2512. 
Einwirkung  v.  Aethyljodid  u.  Zink  auf 

A  a  |3-Fettester.    Ibid.,  Vol.  29,  p.  1791. 
Zur  Kenntniss  der  Additionsvorgange  bei 

den  Natriumderivaten  von  Formyl-  uud 

Acetessigestern,     imd    Nitroathanen. 

Ibid.,  Vol.  29,  pp.  1794-1799. 
Zur     Constitution     der     Oxalessigsaure. 

(With  J.  E.  Bucher.)     Ibid.,  Vol.  29, 

pp.  1792-1793. 
Ueber  die  Regelmassigkeiten  bei  der  Anla- 

gerung  von  Halogenverbindungen  auf 

ungesattigten  Sauren.     Jour.  f.  prakt. 

Chemie,  1889,  Vol.  40,  pp.  171-179. 
Ueber  die  Einwirkung  von  Jodwasserstoff 

auf  die  Krotonsauren.     Ibid.,  Vol,  40, 

pp.  95-96. 
Zur  Kenntniss  der  Lavulinsaure  und  des 

Acetondiessigsauredilaktons.        Ibid., 

Vol.  43,  pp.  113-1.30. 
Ueber  die  Addition  von  Natriumacetessig- 

und  Natriummalonsjiureathern  zu  den 

Aethern  ungesattigter  Sauren.    (With 

P.  C.  Freer.)     Ibid.,  Vol.  39,  pp.  390- 

395. 
Zur  Kenntniss  der  Halogenentziehung  bei 

organischen  a  j8-Halogensaureathern. 

(With  O.  Schulthess.)     Ibid.,  Vol,  39, 

pp.  587-596. 
Ueber  die  Addition  von  Brom  zu  Acetylen- 

dicarbonsaure  und  deren  Althyliither. 

Ibid.,  Vol.  46,  pp.  210-233. 
Ueber    die    Einwirkung    von    Natrium- 

athylat     auf     Dibrombernsteinsaure- 


Published  Papers. 


527 


ather,     (With  C.  C.  Maisch.)     Ibid., 

Vol.  46,  pp.  233-236. 
[Jeber  die  Crotonsaure  vuid  Derivate  der- 

selben.     (With  O.  Scliulthess.)    Ibid., 

Vol.  46,  pp.  236-266. 
Ueber  die  Bildung  von  fester  Crotonsaure 

bei  der  Reduction    von  allo-cc-Brom- 

und-chlorcrotonsaure.     Ibid.,  Vol.  46, 

pp. 266-272. 
Beitrage  zur  Kenntniss  einiger  Homologen 

der  Aepfelsaure.     (With   G.  Tissot.) 

Ibid.,  Vol.  46,  pp.  285-304. 
Ueber  die  Addition  von  Chlor  zu  mehr- 

basischen,    ungesattigten    Fettsauren. 

(With  G.  Tissot.)    Ibid.,  Vol.  46,  pp. 

381-427. 
Ueber  die  Addition  von  Natriumacetessig- 

und    Natriumacetmalonather    zu   den 

Aethern  ungesattigter  Sauren.     Ibid., 

Vol.  49,  pp.  20-25. 
Beitrage  zur  Kenntniss  der  Ringbildung 

bei  organischen,  stickstoffhaltigen  Ver- 

bindungen.     Ibid.,  Vol.  49,  pp.  26-43. 
Untersuchungen        iiber       Alloisomerie. 

Ibid.,  Vol.  49,  pp.  289-372. 
Ueber  das  Verhalten  von   Benzaldehyd 

gegen  Phenol.     Ibid.,  Vol.   57,    334- 

336. 
Ueber  einige  Gesetze  und  deren  Anwen- 

dung    in    der    organischen     Chemie. 

Ibid.,  Vol.  60,  pp.  286-470. 

ALBERT  A.  MICHELSON  :  — 

Midshipman,  U.  S.  Naval  Academy,  1873  ; 
Instructor  in  Physics  and  Chemistry,  ibid., 
1875-79  ;  Nautical  Almanac  Office,  Wash- 
ington, 1880  ;  University  of  Berlin,  1880 ; 
University  of  Heidelberg,  1881  ;  College 
de  France,  ^cole  Polytechnique,  1882  ; 
Professor  of  Physics,  Case  School  of  Ap- 
plied Science,  Cleveland,  0.,  1883-89; 
Corresponding  Member,  British  Associa- 
tion for  the  Advancement  of  Science,  1884  ; 
Associate  Fellow  of  American  Academy 
of  Arts  and  Sciences,  1885;  Ph.D. 
(Honorary) ,  Western  Reserve  University, 
1886  ;  and  Stevens  Institute,  1887  ;  Vice- 
President,  American  Association  for  the 
Advancement  of  Science,  ibid.  ;  Member 
of  National  Academy  of  Sciences,  1888 ; 
Rumford    Medal,    1889 ;     Professor    of 


Physics,  Clark  University,  1889-92  ; 

Head  Professor  of  Physics,  University  of 
Chicago,  1892-  ;  Bureau  International  des 
Poids  et  Measures,  1892-93;  Member, 
Soci^tg  Frangaise  de  Physique,  1893  ;  Fel- 
low, Royal  Astronomical  Society,  1896 ; 
Foreign  Member,  Soci^t^  Hollandaise  des 
Sciences,  1897  ;  Honorary  Member,  Cam- 
bridge Philosophical  Society,  ibid.  ;  Mem- 
ber (for  the  United  States)  of  the  In- 
ternational Committee  of  Weights  and 
Measures,  ibid. ;  Lowell  Lecturer,  1899  ; 
Sc.D.  (Honorary),  University  of  Cambridge 
(England) ;  Honorary  Member  Royal  In- 
stitute, 1899. 

Author  of  :  — 

Experimental  Determination  of  the  Veloc- 
ity of  Light.  Papers  I.  and  II.  Pi-oc. 
A.  A.  A.  8.,  1879  and  1880. 

The  Relative  Motion  of  the  Earth  and 
the  Luminiferous  Ether.  Am.  Jour, 
of  Sci.,  1881,  Vol.  22,  pp.  120-129. 

A  New  Sensitive  Thermometer.  Jou7'. 
de  Physique,  1882. 

Interference  Phenomena  in  a  New  Form 
of  Refractometer.  Am.  Jour,  of  Sci., 
May,  1882,  Vol.  23,  pp.  395-400. 

A  Method  of  Determining  the  Rate  of 
Tuning-Forks.  Am.  Jour,  of  Sci., 
Jan.,  1883. 

Experimental  Determination  of  the  Veloc- 
ity of  Light.  Third  Paper.  Astron. 
Papers,  Nautical  Almanac,  Vol.  2. 

Velocity  of  Light  in  Carbon  Disulphide 
and  Velocity  of  Red  and  Blue  Light 
in  Same.     Ibid. 

M.  Wolf's  Modification  of  Foucault's 
Apijaratus  for  the  Measurement  of 
the  Velocity  of  Light.  Nature,  May  7, 
1885,  Vol.  32,  pp.  6-7. 

Influence  of  Motion  of  the  Medium  on 
the  Velocity  of  Light.  Am.  Jour,  of 
Sci.,  May,  1886,  Vol.  31,  pp.  377-386. 

On  the  Relative  Motion  of  the  Earth  and 
the  Luminiferous  Ether.  (With  E. 
W.  Morley.)  Philosophical  Magazine, 
5th  ser.,  Dec,  1887,  Vol.  24,  pp. 
449-463. 

On  a  Method  for  Making  the  Wave 
Length  of  Sodium  Light  the  Actual 


528 


Titles  of 


and  Practical  Standard  of  Length. 
(With  E.  W.  Morley.)  Am.  Jour,  of 
Sci.,  Dec,  1887,  Vol.  34,  pp.  427-430. 
Philosophical  Magazine,  5th  ser., 
Dec,  1887,  Vol.  24,  pp.  463-466. 

On  the  Feasibility  of  Establishing  a  Light 
Wave  as  the  Ultimate  Standard  of 
Length.  (With  E.  W.  Morley.)  Am. 
Jour,  of  Set,  3rd  ser.,  Sept.,  1889, 
Vol.  38,  pp.  181-186. 

Measurement  by  Light  Waves.  Ihid., 
Feb.,  1890,  Vol.  39,  pp.  115-121. 

A  Simple  Interference  Experiment.  Ibid. , 
March,  1890,  Vol.  39,  pp.  216-218. 

Application  of  Interference  Methods  to 
Astronomical  Measurements.  Philo- 
sophical Magazine,  5th  ser.,  July,  1890, 
Vol.  30,  pp.  1-21. 

Visibility  of  Interference  Fringes  in  the 
Focus  of  a  Telescope.  Ibid.,  March, 
1891,  Vol.  31,  pp.  256-259. 

Application  of  Interference  Methods  to 
Spectroscopic  Measurements.  Ibid., 
April,  1891,  Vol.  31,  pp.  338-346. 

Measurement  of  Jupiter's  Satellites  by 
Interference.  Mem.  Astr.  Soc.  of  the 
Pacific,  1891. 

Les  m^lhodes  interf^rentielles  en  mtool- 
ogie  et  P^tablissement  d'une  longueur 
d'onde  comme  unit6  absolue  de 
longueur.  Bev.  Gen.  des  Sciences,  30 
Juin,  1893.  Translation  in  Nature, 
Nov.  16,  1893.  Abstracts  in  Comptes 
Eendiis  and  Soc.  de  Physique. 

Determination  exp^rimentale  de  la  valeur 
du  mfetre  en  longueur  d'ondes  lumi- 
neuses.  Travaux  et  Memoires  du 
Bureau  International  des  Poids  et 
3Iesures,  Paris,  1895,  Vol.  11,  pp.  3-85. 

On  the  Broadening  of  Spectral  Lines  by 
Temperature  and  Pressure.  Astro- 
physical  Journal,  Nov.,  1895. 

On  the  Conditions  which  Affect  the  Spec- 
trum Photography  of  the  Sun.  Ibid., 
Jan.,  1895. 

On  the  Limit  of  Visibility  of  Fine  Lines 
in  a  Telescope.     Ibid.,  June,  1895. 

The  Relative  Motion  of  the  Earth  and  the 
Ether.  Am.  Jour,  of  Sci.,  4th  ser., 
1897,  Vol.  3.  pp.  475-478. 

Radiation    in   a   Magnetic  Field,  Philo- 


sophical Magazine,  5th  ser.,  July,  1897, 
Vol.  44,  pp.  109-115. 

A  New  Harmonic  Analyser.  (With  S.  W. 
Strattou.)  Am.  Jour,  of  Sci.,  4th 
ser.,  Jan.,  1898,  Vol.  5,  pp.  1-13. 

A  Spectroscope  without  Prisms  or  Grat- 
ings. Ibid.,  4th  ser.,  March,  1898,  Vol. 
5,  pp.  215-217. 

Radiation  in  a  Magnetic  Field,  Astro- 
physical  Journal,  Feb.,  1898. 

The  Echelon  Spectroscope.  Ibid.,  June, 
1898. 

Nouvelle  M^thode  de  tracer  et  d' observer 
des  divisions  de  precision,  form^es  par 
des  traits  lumiueux  sur  fond  noir. 
Travaux  et  Memoires  du  Bureau 
International  des  Poids  et  Mesures, 
Paris,  1899. 

DICKINSON   SERGEANT  MILLEU : 

University  of  Pennsylvania,  1885-88  ; 
Fellow  in  Philosophy,  Clark  Univer- 
sity, 1889-90  ;  Morgan  Fellow,  Har- 
vard University,  1890-91  ;  Walker  Fellow, 
ibid.,  1891-92  ;  A.B.  and  A.M.,  ibid., 
1892  ;  University  of  Berlin,  1892-93  ; 
Ph.D.,  University  of  Halle,  1893;  Asso- 
ciate in  Philosophy,  Bryn  Mawr  College, 
1893-98  ;  Instructor,  Harvard  Univer- 
sity, for  the  year  1899-1900  ;  Member  of 
American  Psychological  Association. 

Author  of  :  — 

The  Meaning  of  Truth  and  Error.  Phil- 
osophical Bevieio,  July,  1893,  Vol.  2, 
pp.  408-425. 

The  Confusion  of  Function  and  Content 
in  Mental  Analysis.  Proc.  Am.  Psy. 
Ass''n,  Dec,  1893,  and  Psychological 
Beview,  Nov.,  1895,  Vol.  2,  pp.  535- 
550. 

The  Relations  of  "Ought"  and  "Is." 
Internat.  Jour,  of  Ethics,  July,  1894, 
Vol.  4,  pp.  499-512. 

Desire  as  the  Essence  of  Pleasure.  Proc. 
Am.  Psy.  Ass'n,  Dec,  1894.  Psycho- 
logical Beview,  March,  1895,  Vol.  2, 
pp.  164-165. 

"The  Will  to  Believe"  and  the  Duty  to 
Doubt.  Internat.  Jorir.  of  Ethics, 
Jan.,  1899,  Vol.  9,  pp.  169-195. 


Published  Papers. 


529 


Professor  James  on  Philosophical  Method. 
Philosophical  Eevieio,  March,  1899, 
Vol.  8,  pp.  166-179. 

WILLIAM   S.    MILLER:  — 

M.l).,  Yale  Medical  School,  1879;  Prac- 
tising Physician,  ibid.,  1879-86;  College 
of  Physicians  and  Surgeons,  New  York, 
1886-87  ;  Lecturer  in  Microscopical  Tech- 
nique, Mt.  Holyoke  College,  1887-88 ; 
Pathologist,  City  Hospital  and  Memorial 
Hospital,  Worcester,  Mass.,  1888-91; 
Scholar  in  Anatomy,  Clark  Univer- 
sity, 1889-91 ;  Fellow,  1891-92  ;  In- 
structor in  Biology,  University  of  Wis- 
consin, 1892-93  ;  Instructor  in  Vertebrate 
Anatomy,  ibid.,  1893-95  ;  on  leave  of 
absence.  University  of  Leipzig,  1895-96  ; 
Assistant  Professor  of  Vertebrate  Anat- 
omy, University  of  Wisconsin,  1895- ; 
Fellow,  Massachusetts  Medical  Society, 
Fellow,  A.  A.  A.  S. ;  Member  Anatomische 
Gesellschaf  t.  Member  Wisconsin  Academy 
of  Arts  and  Sciences. 

Author  of :  — 

The  Lobule  of  the  Lung  and  its  Blood- 
vessels. Anat.  Anzeiger,  1892,  Vol.  7, 
pp.  181-190. 

The  Structure  of  the  Lung.  Jour,  of 
Morph.,  April,  1893,  Vol.  8,  pp.  165- 
188. 

On  the  So-called  Incas  Eyes.  Science, 
Feb.  10,  1893,  Vol.  21,  pp.  74-75. 

The  Anatomy  of  the  Lung.  Bef.  Hand- 
book of  the  Med.  Sciences,  1893,  Vol. 
9,  pp.  571-576. 

The  Anatomy  of  the  Heart  of  Cambarus. 
Trails.  Wis.  Acad,  of  Sciences,  Arts, 
and  Letters,  1895,  Vol.  10,  pp.  327- 
338. 

The  Relation  between  the  Cortex  and 
Medulla  in  the  Cat's  Kidney,  and  an 
Estimation  of  the  Number  of  Glumer- 
uli.     Ibid.,  pp.  525-538. 

The  Lymphatics  of  the  Lung.  Anat.  An- 
zeiger, June  4,  1896,  Vol.  12,  pp.  110- 
114. 

HALCOTT   C.    MORENO:  — 

A.B.,  University  of  Georgia,  1893  ;  A.M., 
ibid.,  1894;   B.L.,  ibid.,  1896;   Tutor  in 
2m 


Mathematics,  ibid.,  1893-97  ;  Scholar 
in  Mathematics,  Clark  University 
1897-98 ;  Fellow,  1898-99. 

SAMUEL    P.    MULLIKEN:  — 

S.B.,  Massachusetts  Institute  of  Tech- 
nology, 1887 ;  Assistant  in  Chemistry, 
University  of  Cincinnati,  1887-88  ;  Gradu- 
ate Student,  University  of  Leipzig,  1888- 
90;  Ph.D.,  University  of  Leipzig,  1890; 
Fellow  in  Chemistry,  Clark  Univer- 
sity, Jan.-June,  1891 ;  Associate  in 
Chemistry,  Bryn  Mawr  College,  1891-92  ; 
Instructor  in  Chemistry,  Clark  Uni- 
versity, 1892-94  ;  Research  Assistant 
to  Professor  Wolcott  Gibbs,  Newport, 
R.I.,  1894-95 ;  Instructor  in  Organic 
Chemistry,  Massachusetts  Institute  of 
Teclmology,  1895-. 

Author  oi :  — 

Ueber  die  Konstitution  der  Chlorzimmt- 
sauren.  (Inaugural-dissertation  der 
Universitat  Leipzig.)  Leipzig,  1890. 
57  pp. 

The  Geometrical  Isomerism  of  the  Chlor- 
cinnamic  Acids.  Technology  Quar- 
terly, 1891,  Vol.  4,  pp.  170-177. 

A  New  Class  of  Organic  Electrosyntheses. 
Am.  Chem.  Jour.,  June,  1893,  Vol.  15, 
pp.  323-333. 

Laboratory  Experiments  on  the  Class  Re- 
actions of  Organic  Substances  and  their 
Identification.  (With  A.  A.  Noyes.) 
First  edition,  17  pp.,  Maclachlan, 
Boston,  1896;  second  edition,  38  pp., 
1897,  and  third  edition,  30  pp.,  1898. 
Chem.  Publishing  Company,  Easton, 
Pa. 

A  Simple  Color  Reaction  for  Methyl  Al- 
cohol. (With  H.  Scudder.)  Am. 
Chem.  Jour.,  March,  1899,  Vol.  21, 
pp.  266-271. 

Reactions  for  the  Detection  of  the  Nitro- 
group.  (With  E.  R.  Barker.)  Ibid., 
pp.  271-276. 

F.    "WILLIAM    MUTHMANN:  — 

Assistant  in  Analytical  Chemistry,  Uni- 
versity of  Munich,  1884-86  ;  Ph.D.,  Uni- 
versity of  Munich,   1886;   Instructor  in 


530 


Titles  of 


Chemistry  and  Crystallography,  ihid., 
1887-89  ;  Decent  in  Chemistry,  Clark 
University,  1889-91 ;  Assistant  in 
Clieniistry,  Academy  of  Science,  Munich, 
1891-94  ;  Docent  in  Chemistry,  University 
of  Munich,  1894-95  ;  Professor  of  Inor- 
ganic and  Analytical  Chemistry,  ihid., 
1895-. 

Author  of :  — 

Ueber    niedere    Oxyde    des    Molybdans. 

(Inaugural  dissertation. )    Liebig^s  An- 

7ialen,  1887,  Vol.  238,  pp.  108-137. 
Ueber   Polymorphic  und    Mischkrystalle 

einiger  organischer  Substanzen.    Zeits. 

f.  Krystallographie,  1889,  Vol.  15,  pp. 

60-79. 
Krystallographisch-chemische       Notizen. 

Ibid.,  1888,  Vol.  15,  pp.  387-403. 
Krystallographische     Untersuchung     der 

Phtalsaure,  und  einigen  Derivate  der- 

selbeu.     (With  W.    Ramsay.)     Ibid., 

1889,  Vol.  17,  pp.  73-84. 
Messelit,  ein  neues  Mineral.     Ibid.,  18S9, 

Vol.  17,  pp.  93-94. 
Untersuchungen  liber  den  Schwefel  und 

das  Selen.     Ibid.,  1890,  Vol.  17,  pp. 

336-367. 
Zur  Frage  der  Silberoxydulverbindungen. 

Ber.  d.  deuts.  chem.  Gesellschaft,  1887, 

Vol.  20,  pp.  983-990. 
Krystallographische  Untersuchung  einiger 

Derivate  der  Terephtalsaure.     Zeits.  f. 

Krystallographie,   1890,  Vol.    17,   pp. 

460-483. 
Ueber  Isomorphimus  einiger  organischer 

Substanzen.     Ibid.,  1891,  Vol.  19,  pp. 

357-367. 
Bemerkung  liber  den  rothen  Phosphor, 

Zeits.  f.  anorg.  Chemie,  1893,  Vol,  4, 

pp.  303-304. 
Untersuchungen  liber  das  Selen.     (With 

Dr.  J.  Schafer.)    Ber.  d.  debits,  chem. 

Gesellschaft,  1893,  Vol.  26,  pp.  1008- 

1016. 
Eine  bequeme  Methode  zur  Darstellung 

von  Baryumpermanganat.     Ibid.,  pp. 

1016-1018. 
Ueber  die  Reindarstellung  von  Rubidium- 

salzen.     Ibid.,  pp.  1019-1020. 
Berichtigung.     Ibid.,  pp.  1425-1426. 


Beitrage  zur  Volumtheorie  der  Krystalli- 
sirten  Korper.  Zeits.  f.  Krystallogra- 
phie, 1894,  Vol.  22,  pp.  497-551. 

Ueber  die  Loslichkeit  der  MischkrystaUe 
einiger  isomorpher  Salzpaare.  (With 
Dr.  O.  Kuntze.)  Ibid.,  1894,  Vol.  23, 
pp.  368-378. 

Ueber  den  sogenannten  Schneebergit. 
Ibid.,  1895,  Vol.  24,  pp.  583-586. 

Schwefelstickstoff.  Ber.  d.  deuts.  chem. 
Gesellschaft,  1896,  Vol.  29,  pp.  340- 
343. 

Zur  quant.  Best,  und  Scheidung  des  Kup- 
fers.  Zeits.  f.  anorg.  Chemie,  1896, 
Vol.  11,  pp.  268-271. 

Ueber  einige  Verbindungen  des  Phosphors 
und  Selens.   Ibid.,  Vol.  13,  pp.  191-199, 

Stickstoffpentasulfid.  Ibid.,  Vol.  13,  pp. 
200-208. 

Loslichkeit  des  Schwefels  Ceroxyduls  in 
Wasser.  Ibid.,  1897,  Vol.  16,  pp.  450- 
462. 

ZusammensetzTing  einiger  Tellurminera- 
len.  Zeits.  f.  Krystallographie,  1898, 
Vol.  29,  pp.  140-145. 

Ueber  Permolydate.  Zeits.  f.  anorg. 
Chemie,  1898,  Vol.  17,  pp.  73-81. 
Also  Ber.  d.  deuts.  chem.  Gesellschaft, 
1898,  Vol.  31,  pp.  1836-1844. 

Doppelthiosulfate  von  Kupfer  und  Ka- 
lium.  Ber.  d.  deuts.  chem.  Gesell- 
schaft, 1898,  Vol.  31,  pp.  1732-1735. 

JOHN    U.    NEF:  — 

A.B.,  Harvard  University  (with  Honors 
in  Chemistry),  1884;  Kirkland  Fellow, 
ibid.,  1884-87;  University  of  Munich, 
1884-87  ;  Ph.D.,  University  of  Munich, 
1886 ;  Professor  and  Director  of  Chemical 
Laboratory,  Purdue  University,  1887-89 ; 
Assistant  Professor  of  Chemistry, 
Clark  University,  1889-92;  Professor  of 
Chemistry  and  Director  of  the  Kent  Chemi- 
cal Laboratory,  University  of  Chicago, 
1892-96  ;  Head  Professor  of  Chemistry 
and  Director  of  the  Kent  Chemical  Lab- 
oratory, ibid.,  1896-. 

Author  of  :  — 

The  Volumetric  Determination  of  Com- 
bined Nitrous  Acid.     (With  Dr.  Kin- 


Published  Papers. 


531 


nicutt.)  Am.  Chem.  Jour.,  Nov.  1883, 
Vol.  5,  pp.  388-389. 

Ueber  einige  Derivate  des  Durols.  Ber. 
d.  deuts.  chem.  Gesellschaft,  1885,  Vol. 
18,  pp.  2801-2807. 

Ueber  Benzochinoncarbonsauren.  Ibid., 
pp.  3496-3499. 

Ueber  Benzochinoncarbonsauren.  Lie- 
big's  Annalen,  1887,  Vol.  237,  pp.  1- 
39. 

Ueber  Py-3-Phenylchinaldinsaure  und 
Py-3-Phenylchinolin.  (With  Dr.  Koe- 
nigs.)  Ber.  d.  dents,  chem.  Gesell- 
schaft, 1886,  Vol.  19,  pp.  2417-2432. 

Ueber  des  Py-3-Phenylchinolin  und  Py- 
3-B-Dichinolyle.  (With  Dr.  Koenigs. ) 
Ibid.,  1887,  Vol.  20,  pp.  622-636. 

Notiz  iiber  die  Cinchoninsaure.  (With 
W.  Muthmann. )  Ibid. ,  1887,  Vol.  20, 
pp.  636-638. 

Nitranilsaure  aus  Chloranil.  Ibid.,  1887, 
Vol.  20,  pp.  2027-2031. 

On  Tautomeric  Compounds.  Part  I. 
Am.  Chem.  Jour.,  Jan.,  1889,  Vol. 
11,  pp.  1-17. 

The  Constitution  of  the  Anilic  Acids. 
Ibid.,  pp.  17-26. 

Ueber  tautomere  Korper.  Liebig''s  An- 
nalen, 1890,  Vol.  258,  pp.  261-318. 

Die  Constitution  des  Benzochinons. 
Jour.  f.  praktische  Chemie,  1890,  Vol. 
42,  pp.  161-188. 

On  Tautomeric  Compounds.  Part  II. 
Am.  Chem.  Joicr.,  June,  1890,  Vol.  12, 
pp.  379-425. 

The  Constitution  of  Benzoquinone.     Part 

I.  Ibid.,  July,  1890,  Vol.  12,  pp. 
463-488. 

Zur  Kenntniss  des  Acetessigathers.  Lie- 
big'' s  Annalen,  1891,  Vol.  266,  pp. 
52-138. 

The  Constitution  of  Benzoquinone.     Part 

II.  Am.  Chem.  Jour.,  June,  1891, 
Vol.  13,  pp.  422-428. 

Ueber  das  zweiwerthige  Kohlenstoffatom. 
Erste  Abh.  Liebig's  Annalen,  1892, 
Vol.  270,  pp.  267-335.  Also  in  Proc. 
of  Am.  Acad,  of  Arts  and  Sciences,  on 
Bivalent  Carbon,  for  1892,  Vol.  27, 
pp.  102-162. 

Zur  Kenntniss  des  Acetessigathers.     Lie- 


big^s    Annalen,   1893,    Vol.   276,   pp. 

200-245. 
Ueber  die  1.3  Diketone.     Ibid.,  1893,  Vol. 

277,  pp.  59-78. 
Ueber  die    Constitution   der   Salze     der 

Nitroparaffine.     Ibid.,  1894,  Vol.  280, 

pp.  263-291.    Also  in  Proc.  of  Am. 

Acad,  of  Arts  and  Sciences,  1894,  Vol. 

29,  pp.  124-150. 
Ueber  das  zweiwerthige  Kohlenstoffatom. 

Zweite  Abh.  Liebig''s  Annalen,  1894, 

Vol.  280,  pp.  291-342.     Also  in  Proc. 

of  Am.   Acad,  of  Arts  and  Sciences, 

1894,  Vol.  29,  pp.  151-193. 

Ueber  das  zweiwerthige  Kohlenstoffatom. 
Dritte  Abh.  Die  Chemie  des  Cyans 
und  des  Isocyans.     Liebig's  Annalen, 

1895,  Vol.  287,  pp.  265-359. 

Ueber  das  zweiwerthige  Kohlenstoffatom. 
Vierte  Abh.  Die  Chemie  des  Me- 
thyleus.  Ibid.,  1897,  Vol.  298,  pp. 
292-374. 

Notiz  iiber  die  Formhydroxamsaure.  Ber. 
d.  deuts.  chem.  Gesellschaft,  1898,  Vol. 
31,  pp.  2720-2721. 

Ueber  das  Phenylacetylen,  seine  Salze, 
und  seine  Halogen  Substitutions  Pro- 
dukte.  Liebig's  Annalen  der  Chemie, 
1899,  Vol.  308,  pp.  264-328. 

Ueber  das  Verhalten  der  tri-  und  tetra- 
halogen-substituirten  Methane.  Ibid., 
1899,  Vol.  308,  pp.  329-333. 

Dissociationsvorgange  bei  den  Alkyla- 
theon  der  Saltpetersaure,  der  Schwe- 
felsaure  und  der  Halogeuwasserstoff- 
sauren.  Ibid.,  1899,  Vol.  309,  pp. 
126-189. 

HERBERT    NICHOLS:— 

B.S.,  Worcester  Polytechnic  Institute, 
1871 ;  Fellow  in  Psychology,  Clark 
University,  1889-91 ;  Ph.D.,  Clark 
University,  1891 ;  Instructor  in  Psy- 
chology, Harvard  University,  1891-93 ; 
Lecturer  in  Psychology,  Johns  Hopkins 
University,  189o-96;  Member  American 
Society  of  Naturalists,  1890 ;  Member 
American  Psychological  Association,  1892. 

Author  of :  — 

The  Psychology  of  Time.  Am.  Jour,  of 
Psy.,  Feb.,  1891,  Vol.  3,  pp.  453-529  ; 


532 


Titles  of 


April,  1891,  Vol.  4,  pp.  60-112.    Henry 
Holt  &  Co.,  N.  Y.,  1891,  140  pp. 

The  Origin  of  Pleasure  and  Pain.  Philo- 
sophical Beview,  July,  1892,  Vol.1  .,pp. 
403-432;  Sept.,  1892,  Vol.  1.,  pp.  518- 
534. 

Experiments  upon  Pain.  Beport  First  An. 
Mtg.  Am.  Psy.  ^ssre.,  Dec,  1892.  Mac- 
millan&Co.,  N.  Y.,  1894. 

Perceptions  of  Kotation.  Ibid.,  Dec,  1892. 
Macmillan  &  Co.,  N.  Y.,  1894. 

Primarj^  Education.  Beport  Special  Cor- 
respondence, Feb.,  1893.  Educational 
Club,  Philadelphia,  1893. 

The  Harvard  Psychological  Laboratory. 
McCliu-e's  Magazi}ie,  Oct.,  1893,Vol.  1, 
pp.  399-409. 

The  Promise  in  Mental  Science.  Ibid., 
Jan.,  1894,  Vol.  2,  pp.  202-203. 

Beitrage  zur  Psychologie  des  Zeitsinns, 
and  Untersuchungen  zur  Psychologie 
und  jEsthetik  des  Rhythmus.  By 
Ernst  Meumann.  Review.  Psycho- 
logical Beview,  Nov.,  1894,  Vol.  1,  pp. 
638-641. 

Our  Notions  of  Number  and  Space.  Ginn 
&  Co.,  Boston,  1894.     201  pp. 

The  Motor  Power  of  Ideas.  Philosophical 
Beview,  March,  1895,  Vol.  4,  pp.  174- 
185. 

William  James.  (Biographical  Sketch.) 
The  Book  Buyer,  March,  1895,  Vol.  12, 
pp.  61-63. 

The  "Feelings."  Philosophical  Beview, 
Sept.,  1895,  Vol.  4,  pp.  506-530. 

Pain  Nerves.  (Discussion.)  Psychologi- 
cal Beview,  Sept.,  1895,  Vol.  2,  487- 
490. 
Psychology  and  Education.  The  Citizen, 
Dec,  1895,  Vol.  1,  pp.  229-230.  Uni- 
versity Extension  Study,  Philadelphia. 

Pain  Nerves.  (Discussion.)  Psychologi- 
cal Beview,  May,  1896,  Vol.  3,  pp.  309- 
313. 

Fear.  By  Angelo  Mosso.  Review.  Ibid., 
July,  1896,  Vol.  3,  pp.  445-447. 

Ueber  Raumwahrnehmungen  im  Gebiete 
des  Tastsinnes.  By  Chas.  Hubbard 
Judd.  Review.  Ibid.,  Sept.,  1896, 
Vol.  3,  pp.  577-578. 

Professor  Baldwin's  New  Factor  in  Evo- 


lution. Tlie  American  Naturalist, 
Sept.,  1896,  Vol.  30,  pp.  697-710. 

Further  Comments  on  Professor  Baldwin's 
New  Factor  in  Evolution.  Ibid., 
Nov.,  1896,  Vol.  30,  pp.  951-954. 

The  Biologic  Origin  of  Mental  Variety,  or 
How  We  came  to  Have  Minds.  Ibid., 
Dec,  1896,  Vol,  30,  pp.  963-975;  Jan., 
1897,  Vol.  31,  pp.  3-16. 

The  Psycho-Motor  Problem.  Am.  Jour. 
of  Insanity,  July,  1897,  Vol.  54,  pp.  59- 
80. 

Psychology  and  Physiology.    Ibid.,  Oct., 

1897,  Vol.  54,  pp.  181-200. 

The  Psychology  of  the  Emotions.  By 
Th.  Ribot.  Review.  Ibid. ,  Oct. ,  1S97 , 
Vol.  54,  pp.  266-270. 

Hallucinations  and  Illusions.  By  Ed- 
mund Parish.      Review.      Ibid.,  Jan., 

1898,  Vol.  54,  pp.  472-474. 

The  New  Psychology.  By  E.  W.  Scrip- 
ture. Review.  Ibid.,  Jan.,  1898, 
Vol.  54,  pp.  474-475. 

The  Psychology  of  Suggestion.  By  Boris 
Sidis.  Review.  Ibid.,  April,  1898, 
Vol.  54,  pp.  643-644. 

The  Genesis  and  Dissolution  of  the  Fac- 
ulty of  Speech,  By  Joseph  Collins. 
Review.  Ibid.,  July,  1898,  Vol.  55. 
p.  184. 

THOMAS   F.  NICHOLS:  — 

A.B.,  Bowdoin  College,  1892  ;  Scholar  in 
Mathematics,  Clark  University,  1892- 
93;  FeUow,  1893-95;  Ph.D.,  Clark 
University,  1895 ;  Assistant  in  Mathe- 
matics, University  of  Wisconsin,  1895-96; 
Assistant  Professor  of  Mathematics,  Ham- 
ilton College,  1896-. 

Author  of :  — 

On  Some  Special  Jacobians.  Mathemati- 
cal Beview,  July,  1896,  Vol,  1,  pp. 
60-80. 

On  the  Generation  of  Certain  Curves  of  the 
Fifth  and  Sixth  Orders.  Ibid.,  April, 
1897,Vol.  1,  pp.  141-153. 

ARTHUR    A.   NOTES:  — 

S.B.,  Massachusetts  Institute  of  Tech- 
nology, 1886;  S.M.,  ibid.,  1887  ;  Assistant 


Published  Papers. 


533 


in  Chemistry,  ibid.,  1887-88;  Ph.D., 
University  of  Leipzig,  1890  ;  Instructor  in 
Chemistry,  Massachusetts  Institute  of 
Technology,  1890-93 ;  Non-resident 
Lecturer  in  Physical  Chemistry,  Clark 
University,  1892-94 ;  Assistant  Pro- 
fessor of  Chemistry,  Massachusetts  Insti- 
tute of  Technology,  1893-97 ;  Associate 
Professor  of  Organic  Chemistry,  ihid., 
1897-99;  Professor  of  Theoretical  and  Or- 
ganic Chemistry,  ihid.,  1899-. 

Author  of :  — 

On  the  Action  of  Heat  upon  Ethylene. 
(With  L.  M.  Norton.)  Am.  Chem. 
Jour.  Oct.,  1886,  Vol.  8,  pp.  362- 
364. 

The  Constitution  of  Benzol.  Technology 
Quarterly,  1887,  Vol.  1,  pp.  79-90. 

On  the  Action  of  Heat  on  Isobutylene. 
Ibid.,  pp.  278-281. 

Note  on  the  Butines.  (With  L.  M.  Nor- 
ton.) Am.  Chem.  Jour.,  Nov.,  1888, 
Vol.  10,  pp.  430-433. 

An  Index  to  the  Literature  of  the  Butines 
and  their  Halogen  Addition  Products. 
Technology  Quarterly,  1888,  Vol,  2, 
pp.  112-122. 

Ueber  die  Abweichungen  von  den  Gasge- 
setzen  in  Losungen.  Zeits.  f.  physik. 
Chemie,  1890,  Vol.  5,  pp.  53-67. 

Ueber  die  gegenseitige  Beeinflussung  der 
Loslichkeit  von  dissociierten  Korpern. 
Ibid.,  1890,  Vol.  6,  pp.  241-267. 

Ueber  vermehrte  Loslichkeit.  Anwen- 
dung  der  Gefrierpunktsbestimmungen 
zur  Ermittelung  der  Vorgange  in 
Losung.  Ibid.,  1890,  Vol.  6,  pp.  385- 
402. 

Ueber  die  Bestimmung  der  elektrolyti- 
schen  Dissociation  von  Salzen  mittels 
Loslichkeitsversuche.  Ibid.,  1892, 
Vol.  9,  pp.  603-632.  Translation  in 
Technology  Quarterly,  1891,  Vol.  4, 
pp.  259-291. 

Ueber  die  WasserstoflBonabspaltung  bei 
den  sauren  Salzen.  Ibid.,  1893,  Vol. 
11,  pp.  495-500.  Translation  in  Tech- 
nology Quarterly,  1892,  Vol.  5,  pp.  342- 
349. 

Influence  of  the  Introduction  of  a  Sul- 


phonic  Acid  Group  upon  the  Power  of 
a  Developer.  (With  W.  K.  Gaylord.) 
Technology  Quarterly,  1893,  Vol.  6,  pp. 
60-61. 

Ueber  die  elektrolytische  Reduction  des 
Nitrobenzols  in  Schv?efelsaurelosung. 
(With  A.  A.  Clement.)  Ber.  d.  deuts. 
chem.  Gesellschaft,  1893,  Vol.  26,  pp. 
990-992.  Translation  in  Technology 
Quarterly,  1893,  Vol.  6,  pp.  62-64. 

Ueber  die  Bestimmung  der  elektrolyti- 
schen  Dissociation  von  Salzen  mittels 
Loslichkeitsversuche.  Zeits.  f.  phy- 
sik. Chemie,  1893,  Vol.  12,  pp.  162-166. 
Translation  in  Technology  Quarterly, 

1893,  Vol.  6,  pp.  237-240. 
Loslichkeit    des    sauren    Kaliumtartrats 

bei  Gegenvrart  anderer  Salze.     (With 

A.    A.   Clement.)      Zeits.    f.    physik. 

Chemie,    1894,   Vol.   13,  pp.  412-416. 
Die   WasserstoflBonabspaltung     bei    dem 

sauren  Kaliumtartrat.    Zeits. f. physik. 

Chemie,  1894,  Vol.  13,  pp.  417-418. 
Kryoskopische  Untersuchungen  mit  Alu- 

minaten  und  Boraten   von  Alkalime- 

tallen.     (With  W.  R.  Whitney.)  Ibid., 

1894,  Vol.  15,  pp.  694-698. 

The  Electrolytic  Reduction  of  Paranitro- 
benzoic  Acid  in  Sulphuric  Acid  Solu- 
tion. (With  A.  A.  Clement.)  Am. 
Chem.  Jour.,  Nov.,  1894,  Vol.  16,  pp. 
511-513. 

Eine  Priif  ung  der  Principe  der  Loslichkeits- 
beeinflussung  und  ein  Vergleich  der 
daraus  imd  aus  der  elektrischen  Leit- 
fahigkeit  berechneten  Dissociations- 
werte.  (With  C.  G.  Abbot.)  Zeits.f. 
physik.  Chemie,  1895,  Vol.  16,  pp. 
125-138.  Translation  in  Technology 
Quarterly,  1895,  Vol.  8,  pp.  47-62. 
Die  Geschv?indigkeit  der  Reaktion 
zwischen  Zlnnchloriir  und  Eisen- 
chlorid.  Eine  Reaktion  dritter  Ord- 
nung.  Zeits.  f.  physik.  Chemie,  1895, 
Vol.  16,  pp.  546-561. 
Synthesis  of  Diphenylbiphenyl  and  its 
Identilication  as  Benzerythrene. 
(With  Rolfe  M.  Ellis.)  Am.  Chem. 
Jour.,  Oct.,  1895,  Vol.  17,  pp.  620-622. 
Also  in  Technology  Quarterly,  1895, 
Vol.  8,  pp.  178-180. 


534 


Titles  of 


Die  Geschwindigkeit  der  Hydrolyse  des 
Salicins  durch  Sauren.  (With  W.  T. 
Hall.)  Zeits.f.  physik.  Chejnie,  1895, 
Vol.  18,  pp.  240-2-44,  Translation  in 
Technology  Quarterly,  1895,  Vol.  8, 
pp.  283-293. 

Beitrag  zur  Kenntniss  der  Gesetze  der 
Geschwindigkeit  von  polymolekiilaren 
Reaktionen.  (With  W.  O.  Scott.) 
Zeits.  f.  physik.  Chcmie,  1895,  Vol. 
18,  pp.  122-132. 

The  Electrolytic  Reduction  of  Paranitro 
Compounds  in  Sulphuric  Acid  Solu- 
tion. (With  J.  T.  Dorrance.)  Ber. 
der  deuts.  chem.  Gesellschaft,  1896, 
Vol.  28,  pp.  2349-2352.  Translation 
in  Jour.  Am.  Chem.  Soc,  1895,  Vol, 
17,  pp.  855-859. 

The  Occurrence  of  Trimethylene  Glycol  as 
a  By-product  in  the  Glycerine  Manu- 
facture. (With  W,  H.  Watkins.) 
Jour.  Am.  Chem.  Soc,  1895,  Vol. 
17,  pp.  890-891.  Also  Technology 
Quarterly,  1895,  Vol.  8,  pp.  261- 
262. 

Die  katalytische  Wirkung  der  Wasser- 
stoffjonen  auf  polymolekulare  Reak- 
tionen. Zeits.  f.  physik.  Chemie, 
1896,  Vol.  19,  pp.  599-606. 

Bemerkung  iiber  das  Gesetz  der  Ge- 
schwindigkeit der  Reaktion  zwischen 
Eisenchlorid  und  Zinnchloriir,    Ibid., 

1896,  Vol.  21,  p,  16. 

Die  innere  Reibung  des  Quecksilber- 
dampfes.  (With  H,  M.  Goodwin.) 
Ibid.,  1896,  Vol.  21,  pp,  671-679. 
Translation  in  Physical  Beview,  Nov.- 
Dec,  1896,  Vol.  4,  pp.  207-216. 

Sind  Diphenyljodonium-  und  Thallium- 
nitrat  isomorph?  (With  C.  W.  Hap- 
good,  Zeits.  f.  physik.  Chemie,  1896, 
Vol.  22,  pp.  464-465. 

Instruction  in  Theoretical  Chemistry. 
Technology  Qiiarterly,  1896,  Vol.  9, 
pp.  323-325. 

Formation  of  Diacetylenyl  (Butadiine) 
from  Copper  Acetylene.  (With  C. 
W.  Tucker.)     Am.  Chem.  Jour.,  Feb. 

1897,  Vol.  19,  pp.  123-128, 
Synthesis  of   Hexamethylene-Glycol  Di- 
ethyl Ether  and  Other  Ethers  from 


Trimethylene    Glycol.      Ibid.,     Nov., 

1897,  Vol.  19,  pp.  766-781. 
Die    Reaktionsgeschwindigkeit    zwischen 

Eisenchloriir,  Kaliuuichlorat  und  Salz- 

saure.     (With  R.  S.  Wason,)     Zeits. 

f.  ijhysik.  Chemie,  1897,  Vol.  22,  pp. 

210-221.     Translation   in  Jour.    Am. 

Chem.  Soc,  1897,  Vol.  19,  pp.   199- 

213. 
Bestimmung  des  osmotischen  Druckes  mit- 

tels  Dampfdruckmessungen.    (With  C. 

G.  Abbot.)     Zeits.  f.  physik.  Chemie, 

1897,  Vol.  23,  pp.  56-77. 
Ueber  die  Auflosungsgeschwindigkeit  von 

festen  Stoffen    in   ihren  eigenen  Lo- 

sungeu.      (With   W.    R.     Whitney.) 

Ibid.,   pp.   689-692.      Translation    in 

Jour.  Am.  Chem.  Soc,  1897,  Vol.  19, 

pp.  930-934. 
Bemerkung  iiber  die  Kinetische  Theorie 

derLosungen.  Zeits.  f.  physik.  Chemie, 

1897,  Vol.  24,  p.  366. 
Qualitative  Chemical  Analysis.    The  Mac- 

millan    Co.,    N.    Y.,    1897.      89    pp. 

Third  edition. 
Laboratory    Experiments    on    the    Class 

Reactions  and  Identification  of  Organic 

Substances.     (With  S.  P.  Mulliken.) 

Chemical  Publishing  Co.,  Easton,  Pa., 

1897.  31  pp.     Second  edition. 
Investigation  of  the  Theory  of  Solubility 

Effect  in  the  case  of  Trionic  Salts, 
(With  E.  H.  Woodworth. )  Jour.  Am. 
Chem.  Soc,  1898,  Vol.  20,  pp.  194- 
201.     Also  Zeits.  f.  physik.    Chemie, 

1898,  Vol.  26,  pp.  152-158. 

The  Reliability  of  the  Dissociation  Values 
Determined  by  Electrical  Conductivity 
Measurements.  Jour.  Am.  Chem. 
Soc,  1898,  Vol.  20,  pp.  517-528.  Also 
Zeits.  f.  physik.  Chemie,  1898,  Vol. 
26,  pp.  699-710. 

The  Solubility  of  Salts  of  Weak  Acids 
in  Stronger  Acids.  (With  David 
Schwartz.)  Jour.  Am.  Chem.  Soc, 
1898,  Vol,  20,  pp.  743-751.  Also  Zeits. 
f.  physik.  Chemie,  1898,  Vol.  27,  pp. 
279-284. 

Die  Theorie  der  Loslichkeitsbeeinflussung 
bei  zweiioningen  Electrolyten  mit 
lauter    verschiedenen    Jonen.     Zeits. 


Published  Papers. 


635 


/.  physik.   Chemie,  1898,  Vol.  27,  pp. 

267-278. 
The  Solubility  of  Acids  in  Solutions  of  the 

Salts  of  Other  Acids.     (With  E.   S. 

Chapita.)     7 fciVZ.,  pp.  442-446.     Trans- 
lation in  Jour.  Am.  Chem.  Soc,  1898, 

Vol.  20,  pp.  751-756. 
Die  Loslichkeit  von  Jod  in  verdiinnten 

Kaliumjodidlosungen.       (With   L.   J. 

Seidensticker. )       Zeits.     f.     physik. 

Chemie,  1898,  Vol.  27,  pp.    357-360. 

Translation  in  Jb?«r.  Am.  Chem.  Soc, 

1899,  Vol.  21,  pp.  217-220. 
Die  Geschwindigkeit  der  Reaktion  zwischen 

Silberacetat     iind       Natriumformiat. 

Eine  Reaktion  dritter  Ordnung.    (With 

G.  T.  Cottle. )    Zeits.  f.  physik.  Chemie, 

1898,  Vol.  27,  pp.  579-584. 

Die  Beziehung  zwischen  osmotischer  Ar- 
beit und  osmotischem  Druck.      Ibid., 

1899,  Vol.  28,  pp.  220-224. 

C.    A.    ORR:  — 

A.B.,  University  of  Michigan,  1887;  Stu- 
dent, Johns  Hopkins  University,  1887-88  ; 
Principal,  High  School,  Salem,  O.,  1888- 
89 ;  Anthropologist,  Solar  Eclipse 
Expedition,  Clark  University,  1889- 
90  ;  Lecturer  in  Latin,  University  of 
Chicago,  1892-  ;  Instructor,  Chicago  High 
Schools,  1894-. 

VICTOR    PAPCKE:  — 

Ph.D.,  University  of  Gottingen,  1888; 
Assistant  in  Chemistry,  Clark  Univer- 
sity, 1889-90 ;  Medical  Student,  Uni- 
versity of  Leipzig,  1893. 

GEORGE  E.   PARTRIDGE:  — 

Special  Student  in  Philosophy,  Clark 
University,  1895-96  ;  Scholar  in  Psy- 
chology, 1896-98 ;  FeUow,  1898-99. 

Author  of:  — 

Second  Breath.     Pedagogical   Seminary, 

April,  1897,  Vol.  4,  pp.  372-381. 
Blushing.     Ibid.,  April,  1897,  Vol.  4,  pp. 

387-394. 
Some  Mental  Automatisms.    (With  E.  H. 

Lindley.)     Ibid.,  July,  1897,  Vol.  5, 

pp.  41-60. 


Reverie.  Ibid.,  April,  1898,  Vol.  5,  pp. 
445-474. 

Child  Study  in  Connection  with  the  Va- 
cation Schools.  (With  H.  S.  Curtis.) 
Report  on  the  Vacation  Schools  and 
Playgrounds,  N.  Y.  City,  Borough  of 
Manhattan  and  the  Bronx,  1898,  pp. 
51-97. 

Experiments  upon  the  Control  of  the 
Reflex.  Am.  Jour,  of  Psy.  (In 
press.) 

T.    RICHARD   PEEDE:  — 

Christian  Biblical  Institute,  New  York, 
1881-84;  Boston  University,  1884-85; 
Special  Student  in  Philosophy  and 
Pedagogy,  Clark  University,  1895-96 ; 
Honorary  Scholar  in  Philosophy, 
1896-97  ;  Pastor,  South  Baptist  Church, 
Worcester,  1895-. 

JOSEPH  DE  PEROTT:  — 

Universities  of  Paris  and  Berlin,  1877-80  ; 
Decent  in  Mathematics,  Clark  Uni- 
versity, 1890-. 

Author  of:  — 

Sur  la  sommation  des  nombres.    Bull,  des 

Sci.  Mathematiques,  1881,  2d  ser. ,  Vol. 

5,  pp.  37-40. 
Sur  l'infinit6  de  la  suite  des  nombres  pre- 
miers.    Ihid.,  pp.  183-184. 
Sur  une  arithm^tique  espagnole  du  16™^ 

si^cle.    Bull,  di  bibliografia  e  di  storia 

delle  scienze  matematiche,   1882,  Vol, 

15,  pp.  163-170. 
Sur  la  recherche  des  diviseurs  des  fonc- 

tions  entiferes.    Bull,  de  la  Soc.  Mathe- 

matique,  1882,  Vol.  10,  pp.  250-251. 
Sur  un  th^or^me  de  Gauss.    Ibid.,  pp.  87- 

88. 
Sur  la  formation  des  determinants  irr^gu- 

liers.      Jour.    f.    Mathematik,    1883, 

Vol.  95,  pp.  232-237. 
Sur  le  problfeme  des  fous.    Bull,  de  la  Soc. 

Mathematique,  1883,  Vol.  11,  pp.  173- 

186. 
Sur  la  formation  des  determinants  irr^gu- 

liers.      Second    M6moire.      Jour.    f. 

Mathematik,   1884,  Vol.  96,  pp.  327- 

348. 


536 


Titles  of 


Demonstration  du  th^orfeme  fondamental 
de  I'algfebre.  Ihid.,  1885,  Vol.  99,  pp. 
141-160. 

Demonstration  de  I'existence  des  racines 
primitives  pour  les  modules  6gaux  k 
des  puissances  de  nombre  premier  im- 
pair. Bull,  des  Set.  Mathematiques, 
1885,  2^  s^r.,  Vol.  9,  pp.  21-24. 

Sur  les  logarithmes  h  un  grand  nombre  de 
d^cimales  et  en  particulier  sur  les  Ta^ 
bles  de  Steinliauser.  Ibid.,  1887,  2« 
ser..  Vol.  11,  pp.  51-60. 

Sur  requation  t2  —  Du2  =  —1.  Jour, 
f.  Mathematik,  1888,  Vol.  102,  pp.  185- 
223. 

Eemarque  au  sujet  du  th^orfeme  d'Euclide 
sur  r  infinite  du  nombre  des  nombres 
premiers.  Am.  Jour,  of  Mathematics, 
1888,  Vol.  11,  pp.  99-138  ;  1891,  Vol. 
12,  pp.  235-308. 

Sur  une  proposition  empirique  enonc^e  au 
Bulletin.  B\dl.  de  la  Soc.  Mathema- 
tique,  1889,  Vol.  17,  pp.  155-156, 

On  a  Theorem  of  Gauss.  J.  H.  U.  Circu- 
lar, 1889,  No.  78,  p.  30. 

The  Gaussian  Interpolation  Theory,  for- 
mulge  for  ?i  =  7,  8,  9.  Quar.  Jour,  of 
Mathematics,  1891,  Vol.  25,  pp.  200- 
202. 

Sur  les  groupes  de  Galois.  Btill.  de  la 
Soc.  Mathematique,  1893,  Vol.  21,  pp. 
61-65. 

Demonstration  de  Pexistence  de  racines 
primitives  pour  tout  module  premier 
impair.  Bull,  des  Set.  Mathematiques, 
1893,  2«  ser.,  Vol.  17,  pp.  66-83. 

Demonstration  de  I'existence  de  racines 
primitives  module  premier  impair. 
Ibid.,  1894,  2e  ser..  Vol.  18,  pp.  64-66. 

Mathematical  Tables.  Sci.  Am.  Supple- 
ment, July  7,  1894,  Vol.  38,  pp.  15436- 
15437. 

The  Theory  of  Numbers.  (Review  of  M. 
Stieltjes's  "Sur  la  theorie  des  nom- 
bres,") Bull,  of  Am.  Math.  Soc, 
June,  1895,  Vol.  1,  pp.  217-232. 

DANIEL    EDWARD   PHILLIPS:  — 

Graduate  West  Virginia  State  Normal 
School,  1890  ;  Principal,  Public  Schools, 
Philippi,  W.  Va.,  1890-91;    A.B.,   Uni- 


versity of  Nashville,  1893;  A.M.,  ibid., 
18!)4  ;  Scholar  in  Psychology,  Clark 
University,  1894-  March,  1895  ;  Pro- 
fessor of  I'edagogy,  Normal  Department, 
University  of  Georgia,  March,  18'.t-')-Jan., 
1897  ;  Honorary  Scholar  in  Psychol- 
ogy, Clark  University,  Jan.-TJune, 
1897;  Fellow,  1897-98;  Ph.D., 
Clark  University,  1898 ;  Professor  of 
Philosophy  and  Education,  University  of 
Denver,  1898-. 

Author  of  :  — 

The  End  of  Education.     22  pp. 

Eeligious  Education.  Peabody  Becord, 
Nov.,  1893,  Vol.  4,  pp.  5:5-60. 

Courses  of  Study  for  Common  Schools, 
Southern  Jour,  of  Ed.,  Oct.,  1896,Vol. 
9,  pp,  472-478. 

Genesis  of  Number  Forms.  Am.  Jour,  of 
Psy.,  July,  1897,  Vol.  8,  pp.  506-527. 

Number  and  its  Application  psychologi- 
cally considered.  Pedagogical  Sem- 
inary, Oct.,  1897,  Vol.  5,  pp.  221-282. 

Some  Remarks  on  Number  and  its  Appli- 
cation. Ibid.,  April,  1898,  Vol,  5,  pp. 
590-599. 

Some  Aspects  of  the  Child  Study  Move- 
ment. Northwestern  Monthly,  Jan., 
1899,  Vol.  9,  pp.  233-237. 

The  Teaching  Instinct.  Pedagogical  Sem- 
inary, March,  1899,  Vol.  6,  pp.  188- 
246. 

Sunday-School  Teaching.  Study,  March, 
1899,  Vol.  4,  pp.  309-313. 

JEFFERSON   R.    POTTER:  — 

A.B.,  Brown  University,  1877 ;  A.M., 
ibid.,  1887;  Instructor, Vermont  Academy, 
1877-78;  State  Normal  School,  Castine, 
Me.,  1878-85;  Professor  of  Pedagogy, 
State  College  of  Kentucky,  1885-88  ;  In- 
structor in  Natural  Sciences,  State  Nor- 
mal School,  Farmington,  Me..  1888-90; 
Scholar  in  Psychology,  Clark  Uni- 
versity, 1890-91 ;  Superintendent  of 
Schools,  Ashland  and  Hopkinton,  Mass., 
1891-92  ;  Superintendent  of  Schools,  Wal- 
pole,  Foxboro,  and  Norfolk,  Mass.,  1892- 
95  ;  Superintendent  of  Schools,  Walpole 
and  Foxboro,  Mass.,  1895-98 ;  Member : 


Published  Papers. 


537 


New  England  Conference  of  Educational 
"Workers ;  New  England  Association  of 
School  Superintendents. 

Author  of :  — 

History  of  Methods  of  Instruction  in 
Geography.  Pedagogical  Seminary, 
Dec,  1891,  Vol.  1,  pp.  415-424. 

J.    O.    QUANTZ:  — 

B.A.,  University  of  Toronto  (Honors  in 
Philosophy  and  Psychology),  1894  ;  Fel- 
low in  Psychology,  University  of  Wiscon- 
sin, 1895-97  ;  Ph.D.,  University  of  Wis- 
consin, 1897  ;  Honorary  Fellow  in  Psy- 
chology, Clark  University,  1897-98 ; 
Honorary  Fellow  in  Philosophy,  Cornell 
University,  1898-99. 

Author  of:  — 

The  Influence  of  the  Color  of  Surfaces  on 
our  Estimation  of  their  Magnitude. 
Am.  Jour,  of  Psy.,  Oct.,  1895,  Vol.  7, 
pp.  26-41. 

Problems  in  the  Psychology  of  Reading. 
Psychological  Bevieio,  Monograph  Sui> 
plement,  Dec,  1897,  pp.  1-51. 

The  Physiology  of  Shorthand.  Phono- 
graphic World,  March,  1898,  Vol.  13, 
pp.  292-293. 

Dendro-psychoses.  Am.  Jour,  of  Psy., 
July,  1898,  Vol.  9,  pp.  449-506. 

An  Analysis  of  the  Muscular  Sensations 
involved  in  Drawing  a  Line. 

HOLLA   R.    RAMSEY:  — 

Assistant  in  Shop,  Indiana  University, 
1894-95;  A.B.,  Department  of  Physics, 
ibid.,  1895;  A.M.,  ibid.,  1898;  Science 
Teacher,  Decatur,  Ind.,  High  School, 
1895-96  ;  Laboratory  Assistant,  Indiana 
University,  1896-97  ;  Professor  of  Physics, 
Westminster  College,  1897-98  ;  Scholar 
in  Physics,  Clark  University,  1898- 
99  ;  Assistant  in  Physics,  Cornell  Univer- 
sity, 1899-. 

Author  of :  — 

A  Photographic  Study  of  Electrolytic 
Cells.  Physical  Beview,  Sept.,  1899, 
Vol.  9,  pp.  189-190,  1  pi. 


JOHN   F.    REIGART:  — 

A.B.,  Dickinson  College,  1888  ;  Principal 
of  High  School,  Chester,  Pa.,  1888-90; 
Scholar  in  Psychology,  Clark  Univer- 
sity, 1890-91 ;  Associate  Professor  in 
Education,  Teachers'  College,  New  York 
City,  1891-92  ;  Professor  of  Psychology 
and  History  of  Education,  ibid.,  1892-97  ; 
Superintendent  Workingman's  School, 
New  York  City,  1897-. 

Author  of :  — 

The  Training  of  Teachers  in  England. 
Pedagogical  Seminary,  Dec,  1891, 
Vol.  1,  pp.  409-415. 

ERNEST   -W.    RETTGER:  — 

Graduate,  Indiana  State  Normal  School; 
1891;  A.B.,  Indiana  University,  1893; 
Principal,  Rensselaer,  Ind.,  High  School, 
1893-94  ;  Instructor  in  Mathematics,  Indi- 
ana University,  1894-95  ;  Fellow  in 
Mathematics,  Clark  University,  1895- 
98;  Ph.D.,  Clark  University,  1898; 
Instructor  in  Mathematics,  Indiana  Uni- 
versity, 1898-. 

Author  of :  — 

Note  on  the  Projective  Group.     Proc.  Am. 

Acad,  of  Set,  July,  1898,  Vol.  33,  pp. 

491-499. 
On  Lie's  Theory  of  Continuous  Groups. 

Am.  Jour,  of  Math.     (In  press.) 

ROBERT   J.  RICHARDSON  :- 

Teacher  in  Public  Schools,  Varna,  Ont., 
1887-90 ;  Graduate,  Ontario  School  of 
Pedagogy,  1891 ;  Student  at  Toronto  Uni- 
versity, 1892-93  ;  Teacher  in  High  School, 
Prescott,  Ont.,  1893-94  ;  B.A.,  University 
of  Toronto,  1897  ;  Graduate  Student, 
ibid.,  1897-98 ;  Fellow  in  Psychology, 
Clark  University,  1898-99. 

Author  of :  — 

A  case  of  Abnormal  Color-Sense  exam- 
ined with  Special  Reference  to  the 
Space-Threshold  of  Colors.  (With  J. 
W.  Baird.)  Univ.  of  Toronto  Studies, 
Psychological  Series,  1898,  pp.  87- 
100. 


538 


Titles  of 


CAMILLE   RIED:  — 

Protestaut  School,  Freiburg,  Baden,  1850- 
52  ;  Classical  Gymnasium,  Lahr,  Baden, 
1852-00 ;  Student  in  Paris,  1862-63  ;  Resi- 
dent in  Paris,  1862-65,  and  1867-70; 
Resident  in  Spain,  1865-67  ;  Student  in 
Freiburg,  1870-71  ;  Student  in  Boston, 
1881-86  ;  Head  of  School  of  Languages, 
Boston,  1887-90  ;  Instructor  in  Modern 
Languages,  Clark  University,  1889- 
91 ;  Instructor,  Nautical  School,  U.  S.  S. 
Enterprise,  1891-94. 

STANLEY   H.  ROOD  : — 

S.B.,  Worcester  Polytechnic,  in  Mechan- 
ical Engineering,  1890  ;  in  Electrical  En- 
gineering, 1891  ;  Instructor  in  Physics, 
ihid.,  1890-93;  Scholar  in  Physics, 
Clark  University,  Sept.,  1893- April, 
1894 ;  Instructor  in  Joinery,  Mechanic 
Arts  High  School,  Boston,  April-June, 
1894  ;  Instructor  in  French,  ihid.^  1894- 
96  ;  Graduate  Student,  Harvard  Univer- 
sity, 1895-96;  Instructor  in  Joinery, 
Manual  Training  High  School,  Worcester, 
1896-. 

ERWIN    W.   RUNKLE:  — 

A.B.,  Western  College,  1890;  Graduate 
Student  in  Psychology  and  Philosophy, 
Yale  University,  1890-93  ;  Lecturer  in  the 
History  of  Philosophy,  ibid.,  1892-93; 
Ph.D.,  Yale  University,  1893;  Assistant 
Professor  of  Psychology  and  Ethics,  Penn- 
sylvania State  College,  1893-99  ;  Honor- 
ary Fellow  in  Psychology,  Clark 
University,  Jan.-June,  1899  ;  Professor 
of  Psychology  and  Ethics,  Pennsylvania 
State  College,  1899-. 

Author  of  :  — 

Education  and  Life.     Free  Lance,  State 

College,  Pennsylvania,  Jan.,  1894,  Vol. 

13,  pp.  96-98. 
Why  do  we  Dream?     J&id,  Oct.  1895, 

Vol.  14,  pp.  5-8. 
Factors  in  Education.     Ibid.,  May,  1896, 

Vol.  15,  pp.  12-18. 
Psychology  and  the  Modem  Novel.    School 

Gazette,  June,  1897,  Vol.  8,  pp.  8-12. 
Review  of  Breuer  and  Freud :    Studien 


iiber    Hysterie.     Am.   Jour,   of  Psy., 

July,  1899,  Vol.  10,  pp.  592-594. 

S.    EDWARD    RYERSON:  — 

M.A.,  Queen's  University,  1895  ;  Fellow 
in  Mathematics,  Clark  University, 
1895-96. 

Died,  March  25,  1896. 

EDMUND   C.    SANFORD:  — 

A.B.,  University  of  California,  1883; 
Teacher  in  Oahu  College,  Hawaiian  Is- 
lands, 1883-85  ;  Student,  Johns  Hopkins 
University,  1885-88 ;  University  Scholar, 
ibid.,  1887 ;  Fellow,  ibid.,  1887-88 ;  Ph.D., 
Johns  Hopkins  University;  1888  ;  Instruc- 
tor in  Psychology,  ibid.,  1888-89 ;  Instruc- 
tor in  Psychology,  Clark  University, 
1889-92  ;  Assistant  Professor  of  Psy- 
chology, 1892- ;  Joint  Editor,  with 
President  Hall  and  Professor  Titchener, 
of  the  American  Journal  of  Psychology  ; 
Member  of  the  American  Psychological 
Association. 

Author  of :  — 

The  Writings  of  Laura  Bridgman.  (Two 
articles.)     Overland  Monthly,  1886-87. 

The  Relative  Legibility  of  the  Small 
Letters.  Am.  Jour,  of  Psy.,  May, 
1888,  Vol.  1,  pp.  402-435. 

Personal  Equation.  Ibid.,  Nov.,  1888; 
Feb.  and  May,  1889,  Vol.  2,  pp.  3-38, 
271-298,  403-430. 

A  Simple  and  Inexpensive  Chronoscope. 
Ibid.,  April,  1890,  Vol.  3,  pp.  174-181. 

Psychology  at  Clark  University.  Ibid., 
April,  1890,  Vol.  3,  pp.  284-285. 

A  Laboratory  Course  in  Physiological 
Psychology.  Ibid.,  April  and  Dec, 
1891  ;  April,  1892,  Vol.  4,  pp.  141- 
155,  303-322,  474-490;  April,  1893, 
Vol.  5,  pp.  390-415  ;  Jan.,  1895,  Vol. 
6,  pp.  593-616;  April,  1896,  Vol.  7, 
pp. 412-424. 

A  New  Visual  Illusion.  Science,  Feb.  17, 
1893,  Vol.  21,  pp.  92-93. 

On  Reaction-Times  when  the  Stimulus  is 
Applied  to  the  Reacting  Hand.  (With 
J.  F.  Reigart.)  Am.  Jour,  of  Psy., 
April,  1893,  Vol.  5,  pp.  351-365. 


Published  Papers. 


539 


A  New  Pendulum  Chronograph.  Ibid.^ 
April,  1893,  Vol.  5,  pp.  385-389. 

Some  Practical  Suggestions  on  the  Equip- 
ment of  a  Psychological  Laboratory. 
Ibid.,  July,  1893,  Vol.  5,  pp.  429-438. 

Notes  on  New  Apparatus.  Ihid.,  Jan., 
1895,  Vol.  6,  pp.  575-584. 

The  Philadelphia  Meeting  of  the  American 
Psychological  Association.  Science, 
Jan.  24,  1896,  Vol.  3,  pp.  119-124. 

The  Vernier  Chronoscope.  Am.  Jour,  of 
Fsy.,  Jan.,  1898,  Vol.  9,  pp.  191-197. 

A  Course  in  Experimental  Psychology. 
D.  C.  Heath  &  Co.,  Boston,  Mass., 
1898.    449  pp. 

CLARENCE  ARTHUR  SAUNDERS: 
B.A.,  King's  College,  Windsor,  N.  S., 
1885;  M.A.,  1888;  Graduate  Student, 
Johns  Hopkins  University,  1889-92  ;  Assis- 
tant, Smithsonian  Institution,  "Washing- 
ton, 1891-92  ;  Fellow  in  Physics,  Clark 
University,  1892-95;  Ph.D.,  Clark 
University,  1895  ;  Professor  of  Mathe- 
matics and  Physics,  Ursinus  College, 
1895-98. 
Died  Dec.  19,  1898. 

Author  of :  — 

The  Velocity  of  Electric  "Waves.  Physical 
Beview,  Sept. -Oct.,  1896,  Vol.  4,  pp. 
81-105. 

ALBERT    SCHINZ:— 

B.A.,  Neuchatel,  1888  ;  M.A.,  ibid., 
1889  ;  Licentiate  in  Theology,  ibid.,  1892  ; 
Student,  University  of  Berlin,  1892-93; 
Student,  Tubingen,  1893  ;  Ph.D.,  Tiibin- 
gen,  1894 ;  College  de  France  at  Sor- 
bonne,  Paris,  1894 ;  Second  Librarian, 
Library  of  Neuchatel,  and  Associate  Pro- 
fessor of  Philosophy,  University  of  Neu- 
chatel, 1896-97  ;  Honorary  Fellow  in 
Psychology,  Clark  University,  1897- 
98  ;  Instructor  in  French,  University  of 
Minnesota,  1898-99  ;  Lecturer  in  French 
Literature,  Bryn  Mawr  College,  1899-. 

Author  of :  — 

La  nature  du  p^ch^ :  6tude  psychologique. 
Delachaux  et  Niestl^,  Neuchatel,  1892. 
134  pp. 


Morale  et  d^terminisme.  Revue  Philoso- 
phique,  Jan.,  1895,  Vol.  39,  pp.  57-75. 

La  philosophic  de  M.  Ernest  Naville.  Be- 
vue  de  Theologie  et  de  Philosophie, 
July,  1895. 

Mysticisme  et  Magie.  Centralblatt  des 
Zofingervereins,  Dec,  1895. 

Le  recent  mouvement  moral  en  Europe  et 
en  Amerique.  Bridel  et  Cie,  Lau- 
sanne, Suisse.  (Imprim^d'aborddans 
La  Bevue  de  Theologie  et  de  Philoso- 
phie, Sept.,  1896.) 

Essai  sur  la  notion  du  miracle,  consid^rd 
du  point  de  vue  de  la  th^orie  de  la 
connaissance.  Delachaux  et  Niestl^, 
Neuchatel,  1897.  35  pp.  (Reprint 
from  La  Bevue  de  Theologie  et  de  Phi- 
losophie, March,  1897.) 

La  morality  de  I'enfant.  Bevue  Philoso- 
phique,  March,  1898,  Vol.  45,  pp.  259- 
295. 

Die  Moralitat  des  Kindes.  Translation 
by  Ch.  Ufer.  Langensalza,  1898.  42 
pp.  (Heft  I.  der  "  Beitrage  zur  Kin- 
derf  orschung. "  ) ' 

Le  positivisme  est  un  m^thode  et  non  un 
syst^me.  Bevue  Philosophique,  Jan., 
1899,  Vol.  47,  pp.  63-75. 

Les  biblioth^ques  publiques  en  Amerique. 
Bibliotheqiie  Universelle,  Lausanne, 
Suisse,  Aug.-Sept.,  1898. 

Les  sports  dans  les  Universit^s  Am^ri- 
caines.  La  Suisse  Universitaire,  Feb. , 
1899. 

L'Universit^  de  Clark  h  Worcester,  Mass. 
Bevue  des  Bevues,  Paris,  July,  1898. 

L'^glise  aux  Etats  Unis  d'Am6rique.  (In 
press. ) 

Translation  of  Dr.  E.  C.  Sanford's  "A 
Course  in  Experimental  Psychology," 
Schleicher  fr^res,  Paris,  1899.  (In 
press. ) 

Chronique  du  f^minisme  aux  Etats-Unis. 
Bevue  de  Morale  Sociale,  Paris,  June, 
1898. 

La  langue  internationale  Esperanto.  La 
Semaine  Litteraire.  Geneve,  Suisse, 
29  Juillet,  1899. 

La  secte  des  Scientistes  Chretiens  aux 
Etats-Unis  d'Am^rique.  Bevue  des 
Bevues,  Paris.     (In  press.) 


540 


Titles  of 


Un  repr^sentant  de  TAgnosticisme  aux 
Etats-Unis,  Robert  G.  IngersoU.  (In 
press.) 

L' Education  des  nfegres  aux  Etats-Unis 
d'Amfirique.  L'institut  de  Tuskegee 
en  Alabama.  La  Semaine  Litteraire. 
Geneve.     21  Octobre,  1899. 

Le  culte  d'Omar  Khayyam.     (In  press.) 

La  Philosopliie  et  le  Sens  Commiin,  Be- 
vice  Philosophique, 'Paris.     (In  press.) 

ALVA   ROY   SCOTT  :  — 

A.B.,  De  Pauw  University,  1886  ;  A.M., 
ibid.,  1889;  Principal,  Leavenworth 
Schools,  1886-87  ;  Student,  McCormick 
Theological  Seminary,  Chicago,  1888-91  ; 
Pastor,  First  Presbyterian  Church, 
Hanover,  111.,  1891-93;  Graduate  Stu- 
dent, Harvard  University,  189-3-94  ;  Hon- 
orary Scholar  in  Psychology,  Clark 
University,  1894-95 ;  Pastor,  First 
Presbyterian  Church,  Worcester,  Mass., 
1894-98. 

COLIN   ALEXANDER   SCOTT:  — 

Student,  College  of  City  of  New  York, 
1877-78 ;  Graduate,  Toronto  Normal 
School,  1879;  Director  of  Instruction  in 
Drawing,  Kingston  Schools,  1883-84 ; 
B.A.,  Queen's  University,  Kingston, 
Ont.,  1885  (Gold  Medalist  with  Honors 
in  Chemistry,  Biology,  and  Geology);  In- 
structor in  Chemistry,  Ladies'  Medical 
College,  Kingston,  1885-86  ;  Science  Mas- 
ter, IngersoU  Collegiate  Institute,  1886-87  ; 
Science  Master,  Ottawa  Collegiate  Insti- 
tute, 1887-94  ;  Fellow  in  Psychology, 
Clark  University,  1894-96;  Ph.D., 
Clark  University,  1896  ;  Head  of  De- 
partment of  Physiological  Psychology  and 
Child  Study,  Chicago  Normal  School, 
1896-. 

Author  of :  — 

Sex  and  Art.  Am.  Jonr.  of  Psy.,  Jan., 
1896,  Vol.  7,  pp.  153-226. 

Old  Age  and  Death.  Ibid.,  June,  1896, 
Vol.  8,  pp.  67-122. 

Childreri"s  Foars  as  Material  for  Expres- 
sion and  a  Basis  of  Education  in  Art. 
Trans.  III.  Soc.  for  Child  Study,  April, 
1898,  Vol.  3,  pp.  12-17. 


E.  W.    SCRIPTURE  :  — 

A.B.,  College  of  the  City  of  New  York, 
1884;  A.M.,  ibid.,  1890;  Universities  of 
Leipzig,  Berlin,  and  Zurich,  1888-90 ; 
Ph.D.,  University  of  Leipzig,  1891  ;  Fel- 
low in  Psychology,  Clark  University, 
1891-92  ;  Instructor  in  Experimental 
Psychology',  Yale  University,  1892-98 ; 
Director  of  the  Yale  Psychological  Labor- 
atory, 1898- ;  Assistant  Editor  of  Ameri- 
can Journal  of  Psychology,  1891-92  ;  Edi- 
tor of  Studies  from  the  Yale  Psychological 
Laboratory,  1893-  ;  Member  :  American 
Psychological  Association  ;  American  So- 
ciety of  Naturalists ;  Fellow,  American 
Association  for  the  Advancement  of 
Science. 

Author  of  :  — 

Vorstellung  und  Gefiihl.  Philos.  Studien, 
1890,  Vol.  6,  pp.  536-542. 

Ueber  den  associativen  Verlauf  der  Vor- 
stellungen.  (Inaugural  Dissertation.) 
Leipzig,  1891,  101  pp.,  and  Philos.  Stu- 
dien, 1891,  Vol.  7,  pp.  50-146. 

Arithmetical  Prodigies.  Am.  Jour,  of 
Psy.,  April,  1891,  Vol.  4,  pp.  1-59. 

The  Problem  of  Psychology.  Mind,  1891, 
Vol.  16,  pp.  30-5-326. 

Zur  Definition  einer  Vorstellung.  Philos. 
Studien,  1891,  Vol.  7,  pp.  213-221. 

Einige  Beobachtungen  iiber  Schwebungen 
und  Differenztone.  Ibid.,  1892,  Vol. 
7,  pp.  630-632. 

The  Need  of  Psychological  Training.  Sci- 
ence, March  4,  1892,  Vol.  19,  pp.  127- 
128. 

An  Instrument  for  Mapping  Hot  and  Cold 
Spots  on  the  Skin.  Ibid. ,  May  6, 1892, 
Vol.  19,  p.  2.58. 

Education  as  a  Science.  Pedagogical  Sem- 
inary, June,  1892,  Vol.  2,  pp.  111- 
114. 

Psychological  Notes.  Am.  Jour,  of  Psy., 
Aug.,  1892,  Vol.  4,  pp.  577-584. 

Tests  on  School  Children.  Educational 
Eevieio,  Jan.,  1893,  Vol.  5,  pp.  52- 
61. 

1st  eine  cerebrale  Entstehung  von  Schwe- 
bungen moglich  ?  Philos.  Studien, 
1893,  Vol.  8,  pp.  638-640. 


Published  Papers. 


541 


Systematized  Graduate  Instruction  in  Psy- 
chology. Science,  July  28,  1893,  Vol. 
12,  pp.  43-44. 

A  System  of  Color-teaching.  Educational 
Beview,  Dec,  1893, Vol.  5,  pp.  464-474. 

Consciousness  under  the  Influence  of  Can- 
nabis indica.  Science.,  Oct.  27,  1893, 
Vol.  22,  p.  233. 

Psychological  Measurements.  Philosophi- 
cal Beview,  Nov.  1893,  Vol.  2,  pp. 
677-689. 

A  New  Reaction-key  and  the  Time  of 
Voluntary  Movement.  (With  J.  M. 
Moore.)  Studies  from  Yale  Psy. 
Lab.,  1892-93,  Vol.  1,  pp.  88-91. 

Drawing  a  Straight  Line :  a  Study  in 
Experimental  Didactics.  (With  C.  I. 
Lyman.)     Ibid.,  pp.  92-96. 

Some  New  Psychological  Apparatus.  Ibid., 
pp.  97-100. 

On  the  Measurement  of  Hallucinations. 
Science,  Dec.  29,  1893,  Vol  22,  p.  353. 

Work  at  the  Yale  Laboratory.  Psycho- 
logical Beview,  Jan.,  1894,  Vol.  1,  pp. 
66-69. 

Ueber  die  Aenderungsempfindlichkeit. 
Zeits.  f.  Psy.  u.  Phys.  d.  Sinnesorgane, 
1894,  Vol.  6,  pp.  ^12-^1^. 

Observation  on  the  Use  of  the  Terminal 
Verb  in  Infant  Speech.  Science,  Feb. 
2,  1894,  Vol.  23,  p.  62. 

New  Materials  for  Color- teaching.  Edu- 
cational Bevieio,  April,  1894,  Vol.  7, 
pp.  382-383. 

The  Use  of  Antiphones.  N.  Y.  Med.  Jour., 
April  7,  1894,  Vol.  59,  p.  43. 

On  the  Adjustment  of  Simple  Psychologi- 
cal Measurements.  Psychological  Be- 
view, May,  1894,  Vol.  1,  pp.  281-282. 

The  Kinesimeter.  (With  E.  B.  Titchener.) 
Am.  Jour,  of  Psy.,  June,  1894,  Vol.6, 
pp.  424-426. 

Accurate  Work  in  Psychology.  Ibid., 
pp.  427-430. 

Some  Psychological  Illustrations  of  the 
Theorems  of  Bernoulli  and  Poisson. 
Ibid.,  pp.  431-432. 

Methods  of  Laboratory  Mind-study.  Fo- 
rum, Aug.,  1894,  Vol.  17,  pp.  721- 
728. 

Aims  and  Status  of  Child  Study.    Educa- 


tional Beview,  Oct.,  1894,  Vol.  8,  pp. 

236-239. 
On  Mean  Values  for  Direct  Measurements. 

Studies  from   Yale   Psy.   Lab.,   1894, 

Vol.  2,  pp.  1-39. 
Remarks  on  Dr.  Gilbert's  Article.     Ibid., 

pp.  101-104. 
Experiments  on  the  Highest  Audible  Tone. 

(With  H.  F.  Smith.)     Ibid.,  pp.  105- 

113. 
On  the  Education  of  Muscular  Control  and 

Power.     (With  T.  L.  Smith  and  E.  M. 

Brown.)     Ibid.,  pp.  114-119. 
A  Psychological  Method   of  determining 

the  Blind -spot.     Ibid.,  pp.  120-121. 
Tests  of  Mental  Ability  as  Exhibited  in 

Fencing.     Ibid.,  pp.  122-124. 
Reaction-time  and  Time-memory  in  Gym- 
nastic Work.     Bep.  Ninth  Meet.  Am. 

Ass'^n  Physical  Education,    1894,   pp. 

44-49. 
On   the   Measurement   of    Imaginations, 

Sci.  Am.,  Feb.  9,  1895,  Vol.  72,  p. 

85. 
The  Nature  of  Science  and  Its  Relation  to 

Philosophy.     Science,  March  29,  1895, 

N.  S.,  Vol.  1,  pp.  350-352. 
Scientific  Child  Study.     Trans.  III.  Soc. 

for  Child  Study,  May,  1895,  Vol.  1, 

pp. 32-37. 
Simple  but  Accurate  Tests  for  Child  Study. 

Ibid.,  pp.  57-60. 
Practical    Computation    of    the   Median. 

Psychological  Beview,  July,  1895,  Vol. 

2,  pp.  376-379. 
The  Second  Year  at  the  Yale  Laboratory. 

Ibid.,  pp.  379-381. 
A  New   Method   of   Computation.      Sci. 

Am.  Supplement,  July  6,  1895,  Vol.  4, 

p.  16270. 
Thinking,  Feeling,  Doing.     Flood  &  Vin- 
cent, Meadville,  Pa.,  1895.     304  pp. 
A  New  Method  of  Making  Lantern  Slides. 

Scientific  American,    Aug.    24,    1895, 

Vol.  73,  p.  123. 
Some  Principles   of    Mental    Education. 

School  Bevieio,  Nov.,  1895,  Vol.  3,  pp. 

533-547. 
A    Method    of    Stereoscopic    Projection. 

Scientific  American,   Nov.   23,    1895, 

Vol.  73,  p.  327. 


542 


Titles  of 


Some  New  Apparatus.  Studies  from 
Tale  Psy.  Lab.,  1895,  Vol.  3,  p.  08- 
109. 

The  Bad  Eye  Factory.     Outlook,  Feb.  29, 

1896,  Vol.  53,  pp.  393-394. 
Untersuchungen    iiber  die  geistige  Ent- 

wickelung  der  Schulkinder.     Zeits.  f. 

Psy.  u.  Phys.  der  Sinnesorgane,  1896, 

Vol.  10,  pp.  161-182. 
Measuring  Hallucinations.     Science,  May 

22,  1896,  N.  S.,  Vol.  3,  pp.  762-763. 
Child  Study  :  Methods  and  Results.     Be- 

port    65th  Meeting  Am.   Institute  of 

Instruction,  pp.  181-188. 
The  Third  Year  at  the  Yale  Laboratory. 

Psychological  Beview,  July,  1896,  Vol. 

3,  pp.  416-421. 
The  Law  of  Rhythmic  Movement.     Sci- 
ence, Oct.  9,  1896,  N.  S.,  Vol.  4,  pp. 

535-536. 
My  Pedagogic  Creed.     School  Journal, 

Dec.  5,  1896,  Vol.  53,  pp.  621-623. 
Nouveaux  Instruments.     Annee  psycholo- 

gique,  1896,  Vol.  3,  pp.  658-664. 
The  Law  of  Size-Weight  Suggestion.    Sci- 
ence, Feb.  5,  1897,  N.  S.,  Vol.  5,  p.  227. 
Sources  of  the  New  Psychology.   Pop.  Sci. 

Mo.,  May,  1897,  Vol.  51,  pp.  98-106. 
Pleasure  without  Other  Sensations.   N.  Y. 

Med.  Jour.,  July  17,  1897,  Vol.  66,  p. 

99. 
Cerebral  Light.     Science,  July  23,  1897, 

N.  S.,  Vol.  6,  pp.  138-139. 
The  New  Psychology.    Walter  Scott,  Lon- 
don, 1897.     500  pp. 
Researches   on    Reaction-time.      Stitdies 

from  Yale  Psy.  Lab.,  1897,  Vol.  4,  pp. 

12-26. 
Researches  on  Voluntary  Effort.     Ibid., 

1897,  Vol.  4,  pp.  69-75. 

New  Apparatus  and  Methods.  Ibid., 
1897,  Vol.  4,  pp.  76-88. 

Elementary  Course  in  Psychological  Meas- 
urements. Ibid.,  1897,  Vol.  4,  pp.  89- 
139. 

On  Binaural  Space.  Ibid.,  1898,  Vol.  5, 
pp.  76-80. 

Researches  on  the  Memory  for  Arm 
Movements.  (With  W.  C.  Cooke  and 
C.  M.  Warren.)  Ibid.,  1898,  Vol.  5, 
pp.  90-92. 


Principles  of  Laboratory  Economy.   Ibid., 

1898,  Vol.  5,  pp.  93-103. 
Reaction-time  in    Abnormal    Conditions 

of  the  Nervous  System.     Medical  Rec- 
ord, 1898,  Vol.  53,  p.  196. 
Electrical  Ansesthesia.     Science,  June  3, 

1898,  N.  S.,  Vol.  7,  p.  776. 
The  Anaesthetic  Effects  of  a  Sinusoidal 

Current  of    High  Frequency.     Ibid., 

March  10,  1899,  N.  S.,  Vol.  9,  p.  377. 
Color    Weakness   and    Color  Blindness. 

Ibid.,  June  2,  1899,  N.  S.,  Vol.  9,  pp. 

771-774. 
Cerebral  Light,      Ibid.,   June   16,   1899, 

N.  S.,  Vol.  9,  pp.  850-851. 
Arousal  of  Instinct  by  Taste.   Ibid.,  June 

23,  1899,  N.  S.,  Vol.  9,  p.  878. 
Anaglyphs  and  Stereoscopic  Projection. 

Ibid.,  Aug.  11,  1899,  N.  S.,  Vol.  10, 

pp.  185-187. 

CHARLES   H.    SEARS:  — 

Graduate,  State  Normal  School,  Westfield, 
Mass.  (four  years'  course),  1883 ;  Princi- 
pal of  Public  Schools,  Cheshire,  Mass., 
1883-85  ;  Teacher,  Prospect  Park  Insti- 
tute, Brooklyn,  N.  Y.,  1885-88;  Teacher 
of  Latin,  State  Normal  School,  Edinboro, 
Pa.,  1888-92;  A.M.,  Allegheny  College, 
1893;  Ph.D.,  Allegheny  College,  1895; 
Principal,  Normal  Department,  Claflin 
University,  1892-97  ;  Honorary  Fellow 
in  Pedagogy,  Clark  University,  1897- 
99. 

Author  of:  — 

Home  and  School  Punishments.  Peda- 
gogical Seminary,  March,  1899,  Vol, 
6,  pp.  159-187. 

ALBERT   E.    SEGSWORTH  : — 

B.A.,  University  of  Toronto,  1890;  Stu- 
dent, University  of  Leipzig,  1890-91  ;  Uni- 
versity of  Toronto,  1891-92 ;  Student, 
University  of  Leipzig,  1892-93  ;  Honor- 
ary Fellow  in  Psychology,  Clark 
University,   1893-94. 

Author  of :  — 

On  the  Difference  Sensibility  for  the 
Valuation  of  Space  Distances  with  the 
Help  of  Arm  Movements.     Am.  Jour. 


Published  Papers. 


54- 


of  Psy.,  June,  1894,  Vol.  6,  pp.  369- 
407. 
Ueber  Innervationsempfindungen.     (Pri- 
vately printed.)     1894.     5  pp. 

BENJAMIN  F.    SHARPE:  — 

A.B.,  Wesleyan  University,  1887  ;  A.M., 
ibid.,  1890  ;  Adjunct  Professor  of  Physics 
and  Biology,  Randolph-Macon  College, 
1887-91 ;  Graduate  Student  and  Scholar, 
Johns  Hopkins  University,  1891-94  ;  Fel- 
lovy  in  Physics,  Clark  University, 
1894-96 ;  Professor  of  Mathematics, 
State  Normal  School,  New  Paltz,  N.  Y., 
1896-97 ;  Fellow  in  Physics,  Clark 
University,  1897-98. 

Author  of :  — 

A  Double  Instrument  and  a  Double 
Method  for  the  Measurement  of 
Sound.  Science,  June  9,  1899,  N.  S., 
Vol.  9,  pp.  808-811. 

An  Advance  in  Measuring  and  Photo- 
gi-aphing  Sounds.  U.  S.  Weather  Bu- 
reau, No.  202,  Washington,  D.  C, 
1899.     18  pp.,  7  pis. 

JOHN   C.    SHAW:  — 

Graduate,  State  Normal  School,  Fairmont, 
W.  Va.,  1889;  Principal  of  Graded 
Schools,  Paw  Paw,  W.  Va.,  1889-90; 
B.S.,  University  of  Nashville,  1892  ;  M.S., 
ibid.,  1894;  L.I.,  Peabody  Normal  Col- 
lege, Nashville,  1893  ;  Principal  of  Public 
School,  Douglassville,  Tex.,  1893-94; 
Teacher  of  Mathematics,  Marshall  Col- 
lege, 1894-95 ;  Scholar  in  Pedagogy, 
Clark  University,  1895-96 ;  Fellow 
in  Psychology,  1896-97 ;  Teacher  in 
State  Normal  School,  West  Liberty,  W. 
Va.,  1897-. 

Author  of :  — 

Chairs  of  Pedagogy  in  the  United  States. 

W.  Va.  School  Journal,  April,  May, 

and  June,  1895. 
A  Test  of  Memory  in  School  Children. 

Pedagogical  Seminary,  Oct.,  1896, Vol. 

4,  pp.  61-78. 
What  Children  like  to  Read.     W.   Va. 

School  Journal,   Charleston,  W.  Va., 

Oct.,  1897,  Vol.  17,  pp.  5-6. 


HENRY  DAVIDSON   SHELDON:  — 

A.B.,  Stanford  University,  1896;  A.M., 
ibid.,  1897  ;  Instructor  in  Department  of 
Education,  ibid.,  1896-97;  Fellow  and 
Assistant  in  Pedagogy,  Clark  Univer- 
sity, 1897-99. 

Author  of :  — 

The  Institutional  Activities  of  American 
Children.  Am.  Jour,  of  Psy.,  July, 
1898,  Vol.  9,  pp.  425-448. 

FREDERIC   D.   SHERMAN:  — 

A.B.,  University  of  Michigan,  1887; 
Principal  of  Berrien  Springs,  Mich., 
School,  1887-88;  Principal  of  Charlotte, 
Mich.,  High  School,  1888-89;  Principal 
of  Bay  City,  Mich.,  High  School,  1889- 
94 ;  Universities  of  Bonn  and  Leipzig, 
1894-97;  Ph.D.,  University  of  Leipzig, 
1897  ;  Professor  of  Psychology  and  Peda- 
gogy, State  Normal  School,  Oshkosh, 
Wis.,  1897-98;  Honorary  FeUow  in 
Psychology,  Clark  University,  Oct.- 
Nov.,  1898  ;  Lecturer  in  History  of  Edu- 
cation, Teachers  College,  Columbia  Uni- 
versity, Dec,  1898-June,  1899  ;  Assistant 
in  Latin,  Erasmus  Hall  High  School, 
Brooklyn,  N.  Y.,  1899-. 

Author  of :  — 

Ueber  das  Purkinje'sche  Phanomen  im 
Centrum  der  Netzhaut.  Philosophische 
Studien,  1897,  Vol.  13,  pp.  434-479. 

TOSHIHIDE   SHINODA:  — 

Graduate,  Higher  Normal  School,  Tokio, 
Japan  ;  Graduate  Student  in  United  States 
and  Europe,  1888-91;  Honorary  Scholar 
in  Pedagogy,  Clark  University,  1889- 
90 ;  Professor  in  Higher  Normal  School, 
Tokio,  Japan,  1891-. 

LOUIS   SIFF:  — 

S.B.,  Cornell  University  (Special  Mention 
in  Mathematics),  1897  ;  Graduate  Student, 
Johns  Hopkins  University,  Oct.,  1897- 
Eeb.,  1898;  Scholar  in  Mathematics, 
Clark  University,  1898-99  ;  Teaching 
Fellow  in  Mathematics,  University  of  Ne- 
braska, 1899-. 


544 


Titles  of 


ERNEST  B.    SKINNER:  — 

A.B.,  Ohio  University,  1888;  Professor 
of  Mathematics,  Amity  College,  College 
Springs,  la.,  1880-91  ;  Scholar  in  Mathe- 
matics,   Clark   University,    1891-92  ; 

Instructor  in  Mathematics,  University  of 
Wisconsin,  18U2-95 ;  Assistant  Professor, 
ihid.,  1895-;  Member  American  Mathe- 
matical Society. 

STEPHEN   E.  SLOCUM  :  — 

B.E.,  Union  University  (Honors  in  Mathe- 
matics and  Physics),  1897  ;  Scholar 
in  Mathematics,  Clark  University, 
1897-98 ;  Fellow,  1898-99. 

Author  of :  — 

Note  on  the  Chief  Theorem  of  Lie's 
Theory  of  Continuous  Groups.  Proc. 
Am.  Acad.     (In  press.) 

JAMES   R.  SLONAKER  :  — 

Graduate,  Indiana  State  Normal  School, 
1889 ;  Supervising  Principal  of  Schools, 
Elroy,  Wis.,  1889-91 ;  University  of  Wis- 
consin, 1891-93;  B.S.,  ibid.,  1893;  Pel- 
low  in  Biology,  Clark  University, 
1893-96 ;  Ph.D.,  Clark  University, 
1896 ;  Instructor  in  Zoology,  Indiana 
University,  1896- ;  Member  Indiana 
Academy  of  Science. 

Author  of:  — 

A  Comparative  Study  of   the  Point  of 

Acute    Vision    in    the    Vertebrates. 

American  Naturalist,  Jan.,  1896,  Vol. 

30,  pp.  24-32. 
A  Comparative   Study   of    the  Area    of 

Acute   Vision  in  Vertebrates.    Jour. 

of  Morph.,   May,   1897,  Vol.   13,  pp. 

445-502. 
The  Fovea.     Proc.  Ind.  Acad,  of  Science, 

1896,  pp.  304-310. 
A  Method  of    Preserving    the    Eye    for 

Sectioning,  or  for  Demonstrating  the 

Area    of    Acute    Vision.       Jour,    of 

Applied  Microscopy,  Feb.,  1896,  Vol. 

1,  p.  18. 
The   Eye  of    the    Mammoth   Cave    Rat. 

Proc.  Ind.  Acad,  of  Science,  1898. 


MAURICE   H.   SMALL:  — 

A.B.,  Colby  University,  1887  ;  Principal, 
High  School,  Norway,  Me.,  1887-92  ; 
ibid.,  Westbrook,  Me.,  1892-95 ;  Scholar 
in  Psychology,  Clark  University, 
1895-96  ;  FeUow,  1896-98  ;  Prin- 
cipal  High  School,  Passaic,  N.  J.,  1898-. 

Author  of :  — 

The  Suggestibility  of  Children.  Peda- 
gogical Seminary,  Dec,  1896,  Vol.  4, 
pp.  176-220. 

Methods  of  manifesting  the  Instinct  for 
Certainty.  Ibid.,  Jan.,  1898,  Vol.  5, 
pp.  313-380. 

An  Experiment  borrowed  from  the  School- 
room. Northwestern  3Ionthly,  Nov., 
1898,  Vol.  9,  pp.  134-135. 

WILLARD    STANTON    SMALL:  — 

A.B.,  Tufts  College,  1894  ;  A.M.,  ibid., 
1897;  Tufts  Divinity  School,  1894-96; 
Professor  of  English  Language  and  Lit- 
erature, Lombard  University,  1896-97 ; 
Scholar  in  Psychology,  Clark  Uni- 
versity, 1897-98;  Fellow,  1898-99. 

Author  of :  — 

Friedrich Nietzsche  (Review).  Pedagogi- 
cal Seminary,  April,  1898,  Vol.  5, 
pp.  606-610. 

Note  on  the  Psychic  Development  of  the 
Young  White  Rat.  Am.  Jour,  of  Psy., 
Oct.,  1899,  Vol.  11,  pp.  80-100. 

•WARREN   R.  SMITH:  — 

A.B.,  Bowdoin  College,  1890  ;  Instructor 
Leicester  Academy,  Leicester,  Mass., 
1890-91  ;  Scholar  in  Chemistry,  Clark 
University,  1891-92  ;  Fellow  in  Chem- 
istry, University  of  Chicago,  1892-94 ; 
Ph.D.,  ibid.,  1894  ;  Assistant  in  Chemistry, 
Bowdoin  College,  1894-95  ;  Instructor  in 
Science,  New  Bedford  High  School,  1895- 
96  ;  Instructor  in  charge  Department  of 
Chemistry,  Lewis  Institute,  Chicago,  111., 
1896-. 

Author  of :  — 

On  the  Addition  Products  of  the  Aro- 
matic Isocyanides.  Am.  Chem.  Jour., 
May,  1894,  Vol.  16,  pp.  372-393. 


Published  Pcqjers. 


545 


HUGH   A.    SNEPP:  — 

A.B.,  Heidelberg  College,  1893  ;  Princi- 
pal, High  School,  Germantown,  O.,  1893- 
94 ;  Tutor  in  Mathematics,  Heidelberg 
College,  1894-95;  Scholar  in  Mathe- 
matics, Clark  University,  1895-96  ; 
Instructor  in  Mathematics  and  Science, 
High  School,  Tiffin,  0.,  1896-98;  Student 
in  Mathematics,  University  of  Chicago, 
Summer  Quarter,  1897. 

FRANK   E.    SPAULDING:  — 

A.B.,  Amherst  College,  1889  ;  Instructor, 
Military  Academy,  Louisville^  Ky.,  1889- 
90  ;  Instructor  and  Associate  Principal, 
ibid.^  1890-91 ;  Student  in  Universities  of 
Leipzig,  Paris,  and  Berlin,  1891-94 ; 
Ph.D.,  University  of  Leipzig,  1894 ; 
Honorary  Fellow  in  Psychology, 
Clark  University,  Oct.,  1894-May, 
1895  ;  Superintendent  of  Schools,  Ware, 
Mass.,  May,  1895- June,  1897;  Superin- 
tendent of  Schools,  Passaic,  N.  J.,  Sep- 
tember, 1897- ;  President,  New  Jersey 
Association  for  the  Study  of  Children  and 
Youth,  1899. 

Author  of:  — 

Richard  Cumberland  als  Begriinder  der 
Englischen  Ethik.  Leipzig,  1894.  xii. 
+  101  pp. 

The  Province  of  the  Elementary  School. 
Jour,  of  Pedagogy,  Sept. ,  1896,  Vol.  9, 
pp.  129-137. 

Mental  Images.  Educational  Founda- 
tions, Sept.,  1897,  Vol.  9,  pp.  15-21. 

The  Dynamics  of  Mental  Images.  Ihid., 
Oct.,  1897,  Vol.  9,  pp.  65-70. 

Some  Psychic  Processes  involved  in  Read- 
ing. Ibid.,  Nov.,  1897,  Vol.  9,  pp.  ISO- 
IS?. 

The  Psychology  of  Defective  Reading. 
Ibid.,  Dec,  1897,  pp.  194-201. 

Mental  Economy  in  Reading.  Ibid. ,  Jan., 
1898,  Vol.  9,  pp.  257-262. 

Psychic  Aspects  of  Learning  to  Read. 
Ibid.,  Feb.,  1898,  Vol.  9,  pp.  S47- 
353. 

Preventing    and    Correcting      Defective 
Reading.     Ibid.,  March,  1898,  Vol.  9, 
pp.  389-395. 
2n 


What  can  One  Read  ?    Ibid.,  April,  1898, 

Vol.  9,  pp.  514-520. 
Psychology   in  Geography.     Ibid.,   May 

and  June,  1898,  Vol.  9,  pp.  572-577, 

619-625. 
The  Elementary  Character  of  Secondary 

Education.     Jour,  of  Pedagogy,  Jan., 

1899,  Vol.  12,  pp.  11-24. 
Immediate  Educational  Work.      Annual 

Report,  Supt.  of  Schools,  Ware,  Mass. , 

Feb.  1,  1896,  pp.  17-22. 
Educational  Policy  and  Aims.    Ibid.,  Feb. 

1,  1897,  pp.  14-32. 
The  Course  of  Study  ;  Grading  and  Pro- 
motion,   etc.     Annual   Report,    Supt. 

of  Schools,  Passaic,  N.  J.,  1897-98,  pp. 

9-64. 

EDWIN   D.    STARBUCK:  — 

A.B.,  Indiana  University,  1890  ;  Teacher 
of  Mathematics  and  Latin,  Spiceland, 
Ind.  Academy,  1890-91  ;  Teacher  of 
Mathematics,  Vincennes  College,  1891-93  ; 
Student  in  Psychology,  Harvard  Univer- 
sity, 1893-95;  A.B.,  ibid.;  1894;  A.M., 
ibid.,  1895;  Fellow  in  Psychology, 
Clark  University,  1895-97  ;  Ph.D., 
Clark  University,  1897  ;  Assistant  Pro- 
fessor of  Education,  Stanford  University, 
1897-. 

Author  of :  — 

A  Study  of  Conversion.  Am.  Jour,  of 
Psy.,  Jan.,  1897,  Vol.  8,  pp.  268-308. 

Some  Aspects  of  Religious  Growth.  Ibid. , 
Oct.,  1897,  Vol.  9,  pp.  70-124. 

Child  Study  and  its  Possibility  as  a  Sci- 
ence. Northwestern  Monthly,  March- 
April,  1899,  Vol.  9,  pp.  358-362. 

Psychology  of  Religion.  With  an  intro- 
duction by  Professor  William  James. 
Contemporary  Science  Series.  (In 
press.) 

ORLANDO   S.    STETSON:  — 

Worcester  Polytechnic  Institute,  1896-98  ; 
Scholar  in  Mathematics,  Clark  Uni- 
versity, 1898-99. 

COLIN   C.    STEWART:  — 

B.A.,  University  of  Toronto,  1894; 
Scholar    in    Physiology,  Clark    Uni- 


646 


Titles  of 


versity,  1894-95  ;  FeUow,  1895-97  ; 
Ph.  D.,  Clark  TJni versity,  1897  ;  As- 
sistant iu  riiysiology,  Harvard  Medical 
School,  1897-98;  Tutor  m  Physiology, 
Columbia  University,  1808- ;  Member 
American  Physiological  Society. 

Author  of:  — 

The  Influence  of  Acute  Alcohol  Poisoning 
on  Nerve  Cells.  Jour,  of  Exp.  Medi- 
cine, Nov.,  1896,  Vol.  1,  pp.  623-629. 

Variations  in  Daily  Activity  produced  by 
Alcohol  and  by  Changes  in  Barometric 
Pressure  and  Diet,  with  a  Description 
of  Recording  Methods.  Am.  Jour,  of 
Physiology,  Jan.,  1898,  Vol.  1,  pp.  40- 
56. 

On  the  Course  of  Impulses  to  and  from 
the  Cat's  Bladder.  Ibid.,  Jan.,  1899, 
Vol.  2,  pp.  182-202. 

A  Simple  Etherizing  Bottle.  Ibid.  (Proc. 
Am.  Physiol.  Soc,  Dec,  1898),  Vol.  2, 
p.  X. 

The  Relaxation  of  the  Cat's  Bladder. 
Ibid.,  Aug.,  1899,  Vol.  3,  pp.  1-8. 

JULIUS   STIEGLITZ:  — 

University  of  Berlin,  1886-89  ;  University 
of  Gottingen,  1888;  Ph.D.,  University  of 
Berlin,  1889;  Scholar  in  Chemistry, 
Clark  University,  Jan.-June,  1890 ; 
Chemist,  Parke,  Davis  &  Co.,  Detroit, 
Mich.,  1890-92;  Docent  in  Chemistry, 
University  of  Chicago,  1892-93  ;  Assistant 
in  Chemistry,  ibid.,  189;3-94  ;  Instructor 
in  Chemistry,  ibid.,  1894-97;  Assistant 
Professor  in  Chemistry,  ibid.,  1897-  ;  Fel- 
low of  the  American  Association  Advance- 
ment of  Science ;  Member,  Deutsche 
Chemische  Gesellschaft. 

Author  of  :  — 

Ueber    das    Verhalten    der    Amidoxime 

gegen  Diazobenzolverbindungen.    Ber. 

d.  deuts.  chem.  Gesellschaft,  1889,  Vol. 

22,  pp.  3148-3160. 
On  Benzoquinone  Carboxylic  Acids.     Am. 

Chem.  Jour.,  1891,  Vol.  13,  pp.  38^2. 
Alkaloidwertbestimmung  von  Extrakten. 

Pharmaceutische  Bundschau,  1892  and 

1893,  3  papers. 


Ferric  Phosphate,  U,  S.  P.,  and  Ferric 
Pyrophosphate,  U.  S.  P.    Journal  of 

Pharmacy,  1891. 

Notes  on  Pyrophosphoric  and  Phosphoric 
Acid.     Ibid.,  1891. 

Derivatives  of  Nitrogen  Halogen  Com- 
pounds. (With  F.  Lengfeld.)  A7n. 
Chem.  Jour.,  1893,  Vol.  15,  pp.  215- 
222,  504-518  ;  Vol.  16,  pp.  370-372. 

The  Action  of  Phosphorus  Pentachloride 
on  Urethanes.  (With  F.  Lengfeld.) 
Ibid.,  1894,  Vol.  16,  pp.  70-78. 

Ueber  Alkylisoharnstoffe.  (WithF.  Leng- 
feld.) Ber.  d.  deuts.  chem.  Gesell- 
schaft, 1894,  Vol.  27,  pp.  926-927. 

Ueber  die  Einwirkung  von  Natrium- 
athylat  auf  Carbodiphenylimid.  Ibid., 
1895,  Vol.  28,  pp.  573-574. 

Ueber  Thiamine.  (With  F.  Lengfeld.) 
Ibid.,  1895,  Vol.  28,  pp.  575-576,  2742- 
2744. 

On  Imidoethers  of  Carbonic  Acid.  (With 
F.  Lengfeld.)  Am.  Chem.  Jour.,  1895, 
Vol.  17,  pp.  98-113. 

On  the  "Beckmann  Rearrangement." 
Ibid.,  1896,  Vol.  18,  pp.  751-761. 

On  the  Constitution  of  the  Salts  of  Imido- 
ethers and  other  Carbimide  Deriva- 
tives. Ibid.,  1899,  Vol.  21,  pp.  101- 
111. 

F.    E.    STINSON:  — 

Iowa  Agricultural  College,  1884-86  ;  Prin- 
cipal, Poplar  Grove  Institute,  Ark.,  1889- 
90;  Instructor  in  Physics  and  Mathematics, 
Paris  Academy,  Ark.,  1890-92;  Scholar 
in  Mathematics,  Clark  University, 
1892-93  ;  Fellow,  1893-95. 

WILLIAM    E.    STORY:  — 

A.B.,  Harvard  University,  1871  ;  Parker 
Fellow,  ibid.,  1874-75;  Universities  of 
Berlin  and  Leipzig,  1871-75;  Ph.D., 
University  of  Leipzig,  1875;  Tutor  of 
Mathematics,  Harvard  University,  1875- 
76 ;  Associate,  Assistant  Professor,  and 
Associate  Professor  of  Mathematics, 
Johns  Hopkins  University,  1876-89  ;  As- 
sociate Editor  iu  Charge,  Amei'ican  Jour- 
nal of  Mathematics,  1878-82  ;  Professor 
of    Mathematics,    Clark    University, 


Published  Papers. 


547 


1889- ;  Editor,  Mathematical  Eeview, 
1896-. 

Author  of:  — 

On  the  Algebraic  Relations  existing  be- 
tween the  Polars  of  a  Binary  Quantic. 
Dissertation  approved  for  the  degree  of 
Ph.D.,  Leipzig,  1875.     58  pp. 

On  the  Elastic  Potential  of  Crystals.  Am. 
Jour,  of  Math.,  1878,  Vol.  1,  pp.  177- 
183. 

Note  on  Mr.  Kempe's  Paper  on  the  Geo- 
graphical Problem  of  the  Jour  Colors. 
Ibid.,  1879,  Vol.  2,  pp.  201-204. 

Note  on  the  "15"  Puzzle.  Ibid.,  1879, 
Vol.  2,  pp.  399-404. 

On  the  Theory  of  Rational  Derivation  on  a 
Cubic  Curve  (followed  by  a  Note  on 
Totients).  Ibid.,  1880,  Vol.  3,  pp. 
356-387. 

On  the  Non-Euclidean  Trigonometry. 
Ibid.,  1881,  Vol.  4,  pp.  332-335. 

On  the  Non-Euclidean  Geometry.  Ibid., 
1882,  Vol.  5,  pp.  180-211. 

On  Non-Euclidean  Properties  of  Conies. 
Ibid.,  1882,  Vol.  5,  pp.  358-381. 

On  the  Absolute  Classification  of  Quadratic 
Loci,  and  on  their  Intersections  with 
each  other  and  with  Linear  Loci. 
Ibid.,  1885,  Vol.  7,  pp.  222-245. 

The  Addition-Theorem  for  Elliptic  Func- 
tions. Ibid.,  1886,  Vol.  8,  pp.  364- 
375. 

A  New  Method  in  Analytic  Geometry. 
Ibid.,  1887,  Vol.  9,  pp.  38-44. 

On  the  Covariants  of  a  System  of  Quan- 
tics.  Math.  Annalen,  1893,  Vol.  41, 
pp.  469-490. 

On  an  Operator  that  produces  all  the  Co- 
variants  and  Invariants  of  any  System 
of  Quantics.  Proc.  London  Math. 
Soc,  1892,  Vol.  23,  pp.  265-272. 

Hyperspace  and  Non-Euclidean  Geometry. 
I.  Mathematical  Beview,  April,  1897, 
Vol.  1,  pp.  169-184. 

J.  RICHARD    STREET:  — 

A.B.,  Victoria  University,  1884;  A.M., 
ibid.,  1888  (with  First  Honors  in  English, 
French,  German,  and  Italian)  ;  Modern 
Language  Master,  Smithville  High  School, 


1885-86;  Walkerton  High  School,  1886- 
87  ;  Principal  Caledonia  High  School, 
Ontario,  1887-95 ;  Associate  Member  of 
the  Board  of  Government  Examiners, 
1891-95  ;  Member  and  Secretary  of  the 
County  Board  of  Examiners  for  Profes- 
sional Teachers'  Certificates,  1889-95 ; 
Sometime  Examiner  in  English,  French, 
and  Gei'man  for  Albert,  Alma,  and  Brant- 
ford  Colleges  ;  Instructor  in  the  Mechanics 
Institute,  Caledonia,  1893-95 ;  Scholar 
in  Pedagogy,  Clark  University,  1895- 
96  ;  Fellow  in  Psychology,  1896-98; 
Ph.D.,  Clark  University,  1898;  Pro- 
fessor of  Pedagogy,  Bible  Normal  College, 
Springfield,  Mass.,  1898-  ;  also  Prof essor  of 
Theory  and  Practice  of  Teaching,  Mount 
Holyoke  College,  1899-. 

Author  of :  — 

A  Study  in  Language  Teaching.  Peda- 
gogical Seminary,  April,  1897,  Vol.  4, 
pp.  269-293. 

A  Study  in  Moral  Education.  Ibid.,  July, 
1897,  Vol.  5,  pp.  5-40. 

A  Genetic  Study  of  Immortality.  Ibid., 
Sept.,  1899,  Vol.  6,  pp.  267-313. 

Linguistic  Interpretation.     (In  press.) 

CHARLES   A.  STRONG:  — 

A.B.,  University  of  Rochester,  1884  ;  A.B., 
Harvard  University,  1885  ;  Rochester 
Theological  Seminary,  1886-86;  Fellow, 
Harvard  University,  1886-87  ;  University 
of  Berlin,  1886-87  ;  Instructor  in  Philoso- 
phy, Cornell  University,  1887-89 ;  Uni- 
versities of  Paris,  Berlin,  and  Freiburg, 
1889-90  ;  Docent  in  Philosophy,  Clark 
University,  1890-91 ;  Associate  Pro- 
fessor of  Psychology,  University  of  Chi- 
cago, 1892-95  ;  Lecturer  in  Psychology, 
Columbia  University,  1895-. 

Author  of :  — 

A  Sketch  of  the  History  of  Psychology 
among  the  Greeks.  Am.  Jour,  of  Psy. , 
Dec,  1891,  Vol.  4,  pp.  177-197. 

Dr.  Mtinsterberg's  Doctrine  of  Mind  and 
Body  and  its  Consequences.  Philo- 
sophical Beview,  March,  1892,  Vol.  1, 
pp.  179-195. 


548 


Titles  of 


Mr.  James  Ward  on  Modern  Psychology. 
Psychological  Beviexo,  Jan.,  1894,  Vol. 

I,  pp.  73-81. 

The  Psychology    of    Pain.     Ibid.,  July, 

1895,  Vol.  2,  pp.  329-347. 

Physical  Pain  and  Pain  Nerves.    Ibid., 

Jan.,  1896,  Vol.  3,  pp.  64-68. 
Consciousness  and  Time.    Ibid.,  March, 

1896,  Vol.  3,  pp.  149-157. 

CHARLES   K.  SWARTZ:  — 

A.B.,  Johns  Hopkins  University,  1888  ; 
University  of  Heidelberg,  1888-89;  Fel- 
low in  Chemistry,  Clark  University, 
1889-90  ;  Gettysburg  Theological  Semi- 
nary, 1890-91  ;  Oberlin  Theological  Semi- 
nary, 1891-92;  B.D.,  ibid.,  1892  ;  Pastor, 
Congregational  Church,  Bellevue,  O., 
1892-. 

HENRY   TABER:  — 

Ph.B.,  Yale  University  (Shefl&eld  Scien- 
tific School),  1882  ;  Johns  Hopkins  Univer- 
sity, 1882-85  and  1886-88  ;  Ph.D.,  Johns 
Hopkins  University,  1888  ;  Assistant  in 
Mathematics,  ibid.,  1888-89;  Decent  in 
Mathematics,  Clark  University.  1889- 
92;  Assistant  Professor  of  Mathe- 
matics, 1892-  ;  Resident  Fellow  Ameri- 
can Academy  of  Arts  and  Sciences ; 
Member :  London  Mathematical  Society ; 
American  Mathematical  Society. 

Author  of: 

On  the  Theory  of  Matrices.    Am.  Jour. 

of  Math.,  July,  1890,  Vol.  12,  pp.  337- 

396. 
On  the  Application  to   Matrices  of  any 

order  of  the  Quaternion  Symbols  S  and 

V.     Proc.  London  Math.  Soc,  Dec. 

II,  1890,  Vol.  22,  pp.  67-79. 

On  Certain  Identities  in  the  Theory  of 
Matrices.  Am.  Jour,  of  Math.,  Jan., 
1891,  Vol.  13,  pp.  159-172. 

On  Certain  Properties  of  Symmetric, 
Skew  Symmetric,  and  Orthogonal 
Matrices.  Proc.  London  Math.  Soc, 
June  11,  1891,  Vol.  22,  pp.  449-469. 

On  the  Matrical  Equation  <^Q  =  ^<p.  Proc. 
A.  A.  A.  S.,  1891,  Vol.  26,  pp.  64-66. 

On  a  Theorem  of  Sylvester's  relating  to 


Non-Degenerate  Matrices.  Ibid. ,  1 892, 
Vol.  27,  pp.  46-55. 

Note  on  the  Representation  of  Orthogonal 
Matrices.  Ibid.,  1892,  Vol.  27,  pp. 
163-164. 

On  the  Linear  Transformations  between 
Two  Quadrics.  Proc.  London  Math. 
Soc,  May  11,  1893,  Vol.  24,  pp.  290- 
306. 

On  Real  Orthogonal  Substitution,  Proc 
A.  A.A.S.,  1893,  Vol.  28,  pp.  212-221. 

On  Orthogonal  Substitution.  Mathemat- 
ical papers  read  at  International  Math- 
ematical Congress,  Chicago,  1893. 
Macmillan  &  Co.,  N.  Y.,  1896.  pp. 
395-400. 

On  Orthogonal  Substitutions  that  can  be 
expressed  as  a  Function  of  a  Single 
Alternate  (or  Skew  Symmetric)  Linear 
Substitution.  Am.  Jour,  of  Math., 
Jan.,  1894,  Vol.  16,  pp.  123-130. 

On  Orthogonal  Substitutions.  Brill.  N.  Y. 
Math.  Soc,  July,  1894,  Vol.  3,  pp.  251- 
259. 

On  the  Automorphic  Linear  Transforma- 
tion of  a  Bilinear  Form.  Proc  A.  A. 
A.  S.,  1894,  Vol.  29,  pp.  178-179. 

On  the  Group  of  Automorphic  Linear 
Transformations  of  a  Bilinear  Form. 
Ibid.,  pp.  371-381. 

On  those  Orthogonal  Substitutions  that 
can  be  generated  by  the  Repetition  of 
an  Infinitesimal  Orthogonal  Substitu- 
tion. Proc.  London  Math.  Soc,  May 
9,  1895,  Vol.  26,  pp.  364-376. 

On  the  Automorphic  Linear  Transforma- 
tion of  an  Alternate  Bilinear  Form. 
Math.  Annalen,  1895,  Vol.  46,  pp.  661- 
583, 

On  Certain  Sub-Groups  of  the  Greneral 
Projective  Group.  Bull.  Am.  Math. 
Soc,  April,  1896,  2d  ser..  Vol.  2,  pp. 
221-233. 

On  a  Twofold  Generalization  of  Stieltje's 
Theorem.  Proc.  London  Math.  Soc, 
June  11,  1896,  Vol.  27,  pp.  613-621. 

Note  on  the  Special  Linear  Homogeneous 
Group.  Bull.  Am.  Math.  Soc,  July, 
1896,  2d  ser..  Vol.  2,  pp.  336-339. 

Note  on  the  Automorphic  Linear  Trans- 
formation of  a  Bilinear  Form.     Proc 


Published  Papers. 


549 


A.  A.  A.  S.,  1896,  Vol.  31,  pp.  181- 
192. 

On  the  Group  of  Real  Linear  Transforma- 
tions whose  Invariant  is  an  Alternate 
Bilinear  Form.     Ibid.,  pp.  336-337. 

Notes  on  the  Theory  of  Bilinear  Forms. 
Bull.  Am.  Math.  Soc,  Jan.,  1897,  2d 
ser.,  Vol.  3,  pp.  156-164. 

On  the  Transformations  between  Two 
Symmetric  or  Alternate  Bilinear  Forms. 
Mathematical  Eeview,  April,  1897,  Vol. 
1,  pp. 120-126. 

On  the  Group  of  Linear  Homogeneous 
Transformations  whose  Invariant  is  a 
Bilinear  Form.     Ibid.,  pp.  154-168. 

On  the  Group  of  Real  Linear  Transforma- 
tions whose  Invariant  is  a  Real  Quad- 
ratic Form.  Froc.  A.  A.  A.  S.,  1897, 
Vol.  32,  pp.  77-83. 

ROBERT   R.    TATNALL:  — 

S.B.,  Haverford  College,  1890;  A.M., 
ibid.,  1891 ;  Graduate  Student,  Johns 
Hopkins  University,  1891-93  ;  Fellow  and 
Assistant  in  Physics,  Northwestern  Uni- 
versity, 1893-94  ;  Graduate  Student,  Johns 
Hopkins  University,  1894-95;  Ph.D., 
Johns  Hopkins  University,  1895 ;  In- 
structor in  Physics,  University  of  Penn- 
sylvania, 1895-97  ;  Honorary  Fellow  in 
PhysicB,  Clark  University,  1897-98; 
Instructor  in  Physics,  Academy  of  North- 
western University,  1899-, 

Author  of :  — 

A  New  Proof  of  the  Fundamental  Equa- 
tion of  the  Spectrometer.  (Note  by 
Professor  Crew  in  Astronomy  and 
Astrophysics,  1892,  pp.  932-933.) 

On  a  New  Method  for  Mapping  the 
Spectra  of  Metals.  (With  H.  Crew.) 
Philosophical  Magazine,  Oct.,  1894, 
5th  ser..  Vol.  38,  pp.  379-386. 

The  Arc-Spectra  of  the  Elements.  (With 
H.  A.  Rowland.)  Astrophysical  Jour- 
nal, Jan.,  Feb.,  and  Oct.,  1895,  and 
April,  1896. 

SAMUEL    N.    TAYLOR:  — 

Ph.B. ,  Wesleyan  University,  Middletown, 
Conn.,     1887 ;     In    Charge    of    Experi- 


mental Laboratory,  Thompson-Houston 
Electric  Works,  Lynn,  Mass.,  1887-91  ; 
Professor  of  Natural  Sciences,  Maine 
Wesleyan  Seminary  and  Female  College, 
1891-93;  Fellow  in  Physics,  Clark 
University,  1893-96;  Ph.D.,  Clark 
University,  1896  ;  Instructor  in  Physics, 
Purdue  University,  1896-99  ;  Associate 
Professor  of  Physics,  Syracuse  Univer- 
sity, 1899- ;  Member  of  Indiana  Acad- 
emy of  Science. 

Author  of :  — 

A  Comparison  of  the  Electromotive  Force 
of  the  Clark  and  Cadmium  Cells. 
Physical  Beview,  Sept.-Oct.,  1898, 
Vol.  7,  pp.  149-170. 

CHARLES  HERBERT  THURBER  :  — 

Ph.B.,  Cornell  University,  1886;  A.M., 
Haverford  College,  1890  ;  Registrar  and 
Secretary,  Cornell  University,  1886-88 ; 
Teacher,  Haverford  College  Grammar 
School,  1888-90;  Special  Agent  U.  S. 
Bureau  of  Education  in  Germany,  1890- 
91 ;  Student,  Royal  Polytechnicum,  Dres- 
den, 1890-91  ;  Instructor  in  French, 
Cornell  University,  1891-93  ;  Professor  of 
Pedagogy,  Colgate  University,  and  Princi- 
pal, Colgate  Academy,  1893-95  ;  Director 
of  Division  of  Child  Study,  Department 
of  Public  Instruction,  State  of  New  York, 
1895-96 ;  Assistant  to  Editor-in-chief, 
Johnson's  "  Universal  Cyclopedia,"  1892- 
94 ;  Editor,  School  Review,  1893-  ;  Editor, 
Transactions  of  Illinois  Society  for  Child 
Study,  1898-99 ;  Dean  of  the  Morgan 
Park  Academy,  Sept.,  1895-April,  1899 ; 
Associate  Professor  of  Pedagogy,  Uni- 
versity of  Chicago,  1895- ;  Director  of 
Cooperating  Work,  ibid.,  April,  1899; 
Honorary  Fellow  in  Pedagogy,  Clark 
University,  Jan.-April,  1899. 

Author  of :  — 

The  Cohesive  Forces  in  American  Nation- 
ality. Cornell  Beview,  1886,  Vol.  13, 
pp.  303-307. 

The  Higher  Schools  of  Prussia  and  the 
School  of  Conference  of  1890.  Bep. 
of  the  ComW  of  Ed.,  1889-90,  Vol.  1, 
pp.  313-418. 


550 


Titles  of 


School  Reform  in  Germany.  Academy, 
April,  1891,  Vol.  6,  p.  92. 

A  History  Lesson  in  German.  Jour,  of 
Education,  Sept.  29,  1892,  Vol.  36,  pp. 
202-203. 

Editor,  L'or  o  el'orpello.  (Heath's  Modern 
Language  Series.)  Boston,  1893.  68  pp. 

Summer  Meetings.  School  Revieiv,  Sept., 
1894,  Vol.  2,  pp.  430-438. 

The  N.  E.  A.  at  Denver,  School  Beview, 
Sept.,  1895,  Vol.  3,  pp.  422-433. 

Report  of  Child  Study  Division,  De- 
partment of  Public  Instruction,  State 
of  New  York,  1895. 

Tabular  Statement  of  Entrance  Require- 
ments to  Representative  Colleges  and 
Universities  of  the  United  States. 
(With  W.  J.  Chase.)  School  Beview, 
June,  1896,  Vol.  4,  pp.  341-414. 

College  Entrance  Requirements.  Proc. 
Ass'n  Colleges  and  Preparatory  Schools 
of  the  Middle  States  and  Maryland. 
Philadelphia  meeting,  1896. 

High  School  Self-Government.  School 
Beview,  Jan.,  1897,  Vol.  5,  pp.  32-35. 

The  Report  of  the  Committee  of  Ten. 
School  Journal,  Jvme,  1897. 

Brennende  Fragen  in  dem  Unterrichtswe- 
sen  der  Vereinigten  Staaten.  Deutsche 
Zeitschrift  fur  Ausldndisches  Unter- 
richtswesen,  July,  1897,  Vol.  2,  pp. 
281-289. 

The  Relation  of  Child  Study  to  Sunday 
School  Work.  Northwestern  Monthly, 
Sept.,  1897,  Vol.  8,  pp.  137-141. 

Is  the  Present  High-School  Course  a  Satis- 
factory Preparation  for  Business  ?  If 
not,  how  should  it  be  modified  ?  Proc. 
N.  E.  A.,  1897,  pp.  808-818. 

Die  Sekundarschulen.  Baumeistef s Hand- 
buch  der  Erziehungs-  imd  Unterrichts- 
lehre,  1897,  Vol.  1,  part  IL,  pp.  589- 
604. 
Report  of  the  Department  of  Child  Study. 
Bep.  State  Super.  Pub.  Instr.,  Albany, 
N.  Y.,  1897,  Vol.  2,  pp.  881-991. 
English  as  it  is  taught.     School  Beview, 

May,  1898,  Vol.  6,  pp.  328-338. 
Plans  for  the  Development  of  Child  Study 
in  the  State  through  the  State  Depart- 
ment.     Trans.    III.    Soc.   for    Child 


Study,  Jan.,  1899,  Vol.  3,  pp.  195- 
198. 

Vittorino  daFeltre.  School  Beview,  May, 
1899,  Vol.  7,  pp.  295-300. 

The  New  Courses  in  Pedagogy.  Madison- 
ensis,  Vol.  25,  pp.  175-176. 

The  Field  and  Work  of  a  College  Chris- 
tian Association.  iVeio  Era,  Vol.  5, 
p.  16. 

Hints  on  Child  Study.  Dep.  Pub.  Instr., 
State  of  New  York. 

Numerous  signed  biographical  and  edu- 
cational articles  in  Johnson's  "  Univer- 
sal Cyclopaedia"  (new  edition),  1892- 
94  ;  1898-99. 

Editor  of  "Twentieth  Century"  Text- 
Books. 

FREDERICK   TRACY:  — 

Pickering  College,  1883-85;  B.A.,  Uni- 
versity of  Toronto,  1889  ;  Fellow  in  Phi- 
losophy, ibid.,  1889-92  ;  Fellow  in  Psy- 
chology, Clark  University.  1892-93  ; 
Ph.D.,  Clark  University,  1893  ;  Lec- 
turer in  Philosophy,  University  of  Toronto, 
1893-  ;  Member  Illinois  Society  for  Child 
Study;  President  Ontario  Child  Study 
Association. 

Author  of  :  — 

The  Testimony  of  Consciousness.  Wood- 
stock Col.  Mon.,  March,  1891. 

The  Language  of  Children.  Proc.  Int. 
Ed.  Congress,  1893. 

The  Psychology  of  Childhood.  D.  C. 
Heath  &  Co.,  Boston,  1893.  2d  ed., 
1894. 

The  New  Psychology.  Can.  Meth.  Mag. , 
Nov.,  1894. 

The  Scottish  Philosophy.  Univ.  of  To- 
ronto Quar.,  Nov.,  1895. 

Hypnotism.  Can.  Meth.  Mag.,  Nov., 
1895. 

Results  of  Child  Study  applied  to  Educa- 
tion. Trans.  III.  Soc.  for  Child  Study, 
1895,  Vol.  1,  No.  4,  p.  12. 

Child  Study  and  Pedagogy.  Proc.  Ont. 
Ed.  Ass'n,  1895. 

Character  as  a  Product  of  Education  in 
Schools.  Overland  Monthly  Publishing 
Co.,  1896. 


Published  Papers. 


551 


A    Syllabus    of   Psychology.       Toronto, 

1896. 
The  Culture  of  the  Spiritual  Life,     il/c- 

Master  Univ.  3Ion.,  Jan.,  1897. 
Die  Kinderpsychologie   in  England  und 

Nord-America.  Die  Kinderfehler,  April 

and    July,   1897,  Vol.    2,    pp.    33-42, 

72-87. 
Results  of  Child  Study.     iV.  Y.  School 

Jour.,  July  10,  17,  and  24,  1897. 
Left-handedness.      Trans.   III.    Sac.  for 

Child   Study,    1897,   Vol.    2,  pp.  68- 

76. 
Child  Study,  its  Practical  Value.     Proc. 

Ont.  Ed.  Ass'n,  1897. 
Sully's  "Studies  of  Childhood."     Ibid., 

1898. 
Psychologic  der  Kindheit.    Translated  by 

J.  Stimpfl.    E.  Wunderlich,  Leipzig, 

1899.     158  pp. 

NORMAN   TRIPLET!  :  — 

A.B.,  Illinois  College,  1889;  Principal 
New  Berlin,  111.,  School,  1889-91  ;  Prac- 
tised Law,  ibid.,  1891-94  ;  Instructor 
in  Physics,  Chemistry,  and  Psychology, 
Quincy,  111.,  High  School,  1894-97  ;  A.M., 
Lidiana  University,  1898 ;  Fellow  in  Psy- 
chology, Clark  University,  1898-99. 

Author  of :  — 

The  Dynamogenic  Factors  in  Pacemaking 
and  Competition.  Am.  Joxir.  of  Psy., 
July,  1898.  Vol.  9,  pp.  507-533. 

FREDERICK   TUCKERMAN  : — 

B.S.,  Boston  University,  1878;  M.D., 
Harvard  Medical  School,  1882 ;  Student, 
London  and  Berlin,  1882-83  ;  Lecturer  in 
Anatomy  and  Physiology,  Massachusetts 
Agricultural  College,  1883-86  ;  Fellow  in 
Vertebrate  Anatomy,  Clark  Univer- 
sity, 1889-90  ;  Student,  Universities  of 
Berlin,  London,  and  Heidelberg,  1892-94  ; 
A.M.  and  Ph.D.,  University  of  Heidel- 
berg, 1894;  Private  Laboratory  at  Amherst, 
Mass. ,  1894- ;  Fellow  of  the  Massachusetts 
Medical  Society,  1883-95;  Member  of: 
American  Society  of  Naturalists,  Boston 
Society  of  Natural  History,  Anatomical 
.'society  of  Germany,  etc. 


Author  of :  — 

Some  Observations  in  Reference  to  Bilat- 
eral Asymmetry  of  Form  and  Function. 
Jour.  Anat.  and  Phys.,  1885,  Vol.  19, 
pp.  307-308. 

Supernumerary  Leg  in  a  Male  Frog  (Rana 
palustris).  Ibid.,  1886,  Vol.  20,  pp. 
516-519,  PI.  xvi. 

The  Tongue  and  Gustatory  Organs  of  Me- 
phitis mephitica,  Quar.  Jour.  Micr. 
Sci.,  1887,  Vol.  28,  pp.  149-167,  PI. 
xi. 

The  Tongue  and  Gustatory  Organs  of  Fiber 
zibethicus.  Jour.  Anat.  and  Phys., 
1888,  Vol.  22,  pp.  135-141,  PI.  vii. 

Note  on  the  Papilla  f  oliata  and  other  Taste 
Areas  of  the  Pig.  Anat.  Anzeiger, 
1888,  Vol.  3,  pp.  69-73. 

An  Interesting  Specimen  of  Taenia  sagi- 
nata.  Zool.  Anzeiger,  1888,  Vol.  11, 
pp.  94-95. 

The  Anatomy  of  the  PapiUa  f  oliata  of  the 
Human  Infant.  Jour.  A^iat.  and  Phys., 
1888,  Vol.  22,  pp.  499-501,  PI.  xviii. 

Antipyrine  in  Cephalalgia.  N.  Y.  Med. 
Becord,  1888,  p.  180. 

Observations  on  the  Structure  of  the  Gus- 
tatory Organs  of  the  Bat  (Vespertilio 
subulatus).  Jour.  o/ilforpA.,  1888,Vol. 
2,  pp.  1-6,  PL  i. 

Supplementary  Note  on  Taenia  saginata. 
Zool.  Anzeiger,  1888,  Vol.  11,  pp.  473- 
475,  figures. 

Anthropometric  Data  Relating  to  Students 
of  the  Massachusetts  Agricultural  Col- 
lege.    Amherst,  1888. 

On  the  Gustatory  Organs  of  Putorius  vi- 
son.  Anat.  Anzeiger,  1888,  Vol.  3,  pp. 
941-942. 

On  the  Gustatory  Organs  of  Vulpes  vul- 
garis. Jour.  Anat.  and  Phys.,  1889, Vol. 
23,  pp.  201-205. 

On  the  Gustatory  Organs  of  Arctomys  mo- 
nax.  Anat.  Anzeiger,  1889,  Vol.  4,  pp. 
334-335. 

On  the  Development  of  the  Taste-Organs 
of  Man.  Jour.  Anat.  and  Phys.,  1889, 
Vol.  23,  pp.  559-582. 

On  the  Gustatory  Organs  of  Sciirrus  caro- 
linensis.  Microscope,  1889,  Vol.  9,  pp. 
193-196,  PI.  vii. 


552 


Titles  of 


On  the  Gustatory  Organs  of  Erethizon  dor- 
satus.  Am.  Mo.  Micr.Jour.,  1889,  Vol. 
10,  p.  181. 

An  Hitherto  Undescribed  Taste  Area  in 
Perameles  nasuta.      Anat.   Anzeiger, 

1889,  Vol.  4,  pp.  411-412,  figure. 

On  the  Gustatory  Organs  of  the  American 

Hare  (Lepus  americanus).    Am.  Jour. 

of  Set,  1889,  Vol.  38,  pp.  277-280. 
Note  on  the  Tongue  of  Chrysotis  sestiva. 

Microscope,  1889,  Vol.  9,  pp.  289-290. 
The  Gustatory  Organs  of   Belideus  ariel. 

Jour.  Anat.  and  Phys.,  1889,  Vol.  24, 

pp.  85-88,  PI.  V. 
Further  Observations  on  the  Development 

of  the  Taste-Organs  of  Man.      Ibid., 

pp.  130-131. 
The  Gustatory  Organs  of  Procyon  lotor. 

Ibid.,  pp.  156-159,  PI.  x. 
On  the  Gustatory  Organs  of  the  Mammalia. 

Froc.  Boston  So.  Nat.  Hist.,  1890,  Vol. 

24,  pp.  470-482. 
On  the  Gustatory  Organs  of  some  Eden- 
tata.     Internat.  Monats.  f.  Anat.   u. 

Phys.,  1890,  Vol.  7,  pp.  335-339. 
On  the  Gustatory  Organs  of  some  of  the 

Mammalia.    Jour.  ofMorph.,  1890,  Vol. 

4,  pp.  151-193. 
The  Development  of  the  Gustatory  Organs 

in  Man.     Am.  Jour,  of  Psy.,  April, 

1890,  Vol.  3,  pp.  195-197. 

On  the  Gustatory  Organs  of  Sciurus  hud- 
sonius.  Internat.  Monats.  f.  Anat. 
u.  Phys.,  1891,  Vol.  8,  pp.  137-139, 
PI.  xi. 

Observations  on  some  Mammalian  Taste- 
Organs.  Jour.  Anat.  and  Phys.,  1891, 
Vol.  25,  pp.  505-508. 

On  the  Terminations  of  the  Nerves  in  the 
Lingual  Papillae  of  the  Chelonia.  Iji- 
ternat.  Monats.  f.  Anat.-u.  Phys.,  1892, 
Vol.  9,  pp.  1-5,  PL  i. 

The  Gustatory  Organs  of  Ateles  ater. 
Jour.  Anat.  and  Phys.,  1892,  Vol.  26, 
pp.  391-393. 

Further  Observations  on  the  Gustatory 
Organs  of  the  Mammalia.  Jour,  of 
Morph.,  1892,  Vol.  7,  pp.  69-94. 

Note  on  the  Structure  of  the  Mammalian 
Taste-Bulb.  Anat.  Anzeiger,  1893,Vol. 
8,  pp.  366-367. 


The  Development  of  the  Organs  of  Taste. 
Reference  Hand-book  of  the  Medical 
Sciences,  1893,  Vol.  9,  pp.  857-859,  fig- 
ures, 600-607. 

JOHN   N.  VAN   DER   VRIES:  — 

A.B.,  Hope  College,  1896;  Principal  of 
School,  East  Saugatuck,  Mich.,  1896-97; 
Scholar  in  Mathematics,  Clark  Uni- 
versity, 1897-98 ;  FeUow,  1898-99. 

FRANK   L.   O.  "WADSWORTH:  — 

E.M.,  Ohio  State  University,  1888;  M.E., 
ibid.,  1889;  B.S.,  ibid.,  1889;  Assistant 
in  Physics,  ibid.,  1888-89;  Fellow  in 
Physics,  Clark  University,  1889-90; 
Fellow  and  Assistant,  1890-92  ; 
Special  Assistant  and  Delegate  from 
the  Smithsonian  Institution  to  the  Bu- 
reau Internationale  des  Poids  et  Mesures, 
Paris,  1892 ;  Senior  Assistant  in  Charge, 
Astrophysical  Observatory,  Smithson- 
ian Institution,  1892-94;  Assistant  Pro- 
fessor in  Physics,  University  of  Chicago, 
1894-96 ;  Assistant  Professor  of  Astro- 
physics, Yerkes  Observatory,  1896-97  ;  As- 
sociate Professor  of  Astrophysics,  ibid., 
1897-98;  Special  Engineering  and  Expert 
Work,  Pittsburg  and  Washington,  1898- 
99 ;  Director  of  the  Allegheny  Observa- 
tory, May,  1899- ;  Assistant  Editor,  As- 
trophysical Journal;  Associate  Editor, 
Harpefs  Scientific  Memoirs  ;  Member  As- 
tronomical and  Astrophysical  Society  of 
America. 

Author  of :  — 

Some  New  Forms  of  Dynamos.  Electrical 
World,  Sept.  13,  1890,  Vol.  16,  pp.  183- 
184. 

On  the  Relation  between  Rise  of  Temper- 
ature and  Current  in  Electric  Conduc- 
tors. Ibid.,  Feb.  27,  1892,  and  March 
12,  1892,  Vol.  19,  pp.  145-146,  180- 
181. 

Application  of  Interference  Methods  to 
Base  Line  Measurement.  Philosophi- 
cal Society,  Washington,  Nov.,  1892. 

Report  of  the  Smithsonian  Astrophysical 
Observatory.  Smithsonian  Ann.  Hep., 
Appendix  V.,  1893,  pp.  60-67. 


Puhlished  Papers. 


553 


Electric  Controls  and  Governors  for  Astro- 
nomical Instruments.  Astronomy  and 
Astrophysics,  April,  1894,  Vol.  13,  pp. 
265-272. 

A  Simple  Method  of  determining  the  Ec- 
centricity of  a  Graduated  Circle  with 
One  Vernier.  Am.  Jour.  ofSci.,  May, 
1894,  3d  ser.,  Vol.  47,  pp.  373-376. 

The  Manufacture  of  Very  Accurate  Straight 
Edges.  Jour,  of  the  Franklin  Institute, 
July,  1894,  Vol.  20,  pp.  138.  Ke- 
printed  in  American  Machinist,  Aug. 
2,  1894. 

An  Improved  Form  of  Littrow  Spectro- 
scope. Philosophical  Magazine,  July, 
1894,  5th  ser..  Vol.  38,  pp.  137-142. 

A  New  Design  for  Large  Spectroscope  Slits. 
Am.  Jour,  of  Set,  July,  1894,  3d  ser., 
Vol.  48,  pp.  19-20. 

Some  New  Double  Motion  Mechanisms. 
Astronomy    and    Astrophysics,    Aug., 

1894,  Vol.  13,  pp.  527-528.     Reprinted 
in  Zeits.  f.  Instrumentenkunde,  Jan., 

1895,  Vol.  15,  pp.  32-35. 

Fixed  Arm  Spectroscopes.  Philosophical 
Magazine,  Oct.,  1894,  5th  ser..  Vol.  38, 
pp.  .337-351.  Reprinted  in  Astronomy 
and  Astrophysics  as  No.  9  of  the  series. 
The  Modern  Spectroscope,  Dec,  1894, 
Vol.  13,  pp.  835-849. 

Ein  neuer  Spektroskopspalt  mit  Doppel- 
bewegung.  Zeits.  f.  Instrumenten- 
kunde, Oct.,  1894,  Vol.  14,  pp.  364-366. 

A  Simple  Method  of  mounting  an  Equa- 
torial Axes  on  Ball  Bearings.  As- 
tronomy and  Astrophysics,  Nov.,  1894, 
Vol.  13,  pp.  723-728. 

A  New  Method  of  magnetizing  and  asta- 
tizing  Galvanometer  Needles.  Philo- 
sophical Magazine,  Nov.,  1894,  5th 
ser..  Vol.  38,  pp.  482-488. 

An  Improved  Form  of  Interrupter  for 
Large  Induction  Coils.  Am.  Jour,  of 
Set,  Dec,  1894,  3d  ser.,  Vol.  48, 
pp.  496-501. 

Description  of  a  Very  Sensitive  Form  of 
Thomson  Galvanometer  and  Some 
Methods  of  Galvanometer  Constrac- 
tion.  Philosophical  Magazine,  Dec, 
1894,  5th  ser.,  Vol.  38,  pp.  653-558. 

General    Considerations    respecting    the 


Design  of  Astronomical  Spectroscopes. 
Forming  No.  10  of  the  series,  The 
Modern  Spectroscope.  Astrophysical 
Journal,  Jan.,  1895,  Vol.  1,  pp.  62-79. 

Bemerkungen  liber  Versilberungsfliissig- 
keiten  und  Versilberung.  Zeits.  f. 
Instrumentenkunde,  Jan.,  1895,  Vol. 
15,  pp.  22-27.  Reprinted  in  the  Astro- 
physical  Journal,  March,  1895,  Vol.  1, 
pp.  252-260. 

The  Design  of  Electric  Motors  for  Con- 
stant Speed.  Astrophysical  Journal, 
Feb.,  1895,  Vol.  1,  pp.  169-177. 

Some  New  Designs  of  Combined  Grating 
and  Prismatic  Spectroscopes  of  the 
Fixed  Arm  Type  and  a  New  Form  of 
Objective  Prism.  Forming  No.  11  of 
the  series.  The  Modern  Spectroscope. 
Ibid.,  March,  1895,  Vol.  1,  pp.  232- 
247. 

Einfacher  Unterkrecher  fiir  grosse  Induk- 
tionsapparate.  Zeits.  f.  Instrumenten- 
kunde, July,  1895,  Vol.  15,  pp.  248- 
260. 

A  New  Multiple  Transmission  Prism  of 
Great  Resolving  Power.  No.  13  of  the 
series,  The  Modern  Spectroscope.  As- 
trophysical Journal,  Nov.,  1895,  Vol. 
2,  pp.  264-282. 

Fixed  Arm  Concave  Grating  Spectro- 
scopes. No.  14,  The  Modern  Spectro- 
scope. Ihid.,  Dec,  1896,  Vol.  2,  pp. 
370-382. 

A  Very  Simple  and  Accurate  Cathe- 
tometer.  Am.  Jour,  of  Sci,  Jan.,  1896, 
Vol.  1,  pp.  41-49.  Reprinted  in  Phil- 
osophical Magazine,  Feb.,  1896,  Vol. 
41,  123-133. 

The  Use  and  Mounting  of  the  Concave 
Grating  as  an  Analyzing  or  Direct 
Comparison  Spectroscope.  No.  15, 
The  Modern  Spectroscope.  Astro- 
physical  Journal,  Jan.,  1896,  Vol,  3, 
pp.  47-62. 

A  Simple  Optical  Device  for  completely 
isolating  or  cutting  out  any  Desired 
Portion  of  the  Diffraction  Spectrum 
and  Some  Further  Notes  on  Astro- 
nomical Spectroscope.  No.  16,  The 
Modern  Spectroscope.  IMd.,  Marchj 
1896,  Vol.  3,  pp.  149-192. 


554 


Titles  of 


A  Note  on  Mr.  Burch's  Method  of  Draw- 
ing Hyperbolas  and  on  a  New  Hyper- 
bolagraph.  rhilosophical  Magazine, 
April,  1896,  Vol.  41,  pp.  372-378. 

Review  of  Boy's  Work  on  the  Newtonian 
Constant  of  Gravitation.  Astrophysical 
Journal,  April,  1896,  Vol.  3,  pp.  303- 
311. 

The  Conditions  of  Maximum  Efficiency  in 
the  Use  of  the  Spectrograph.  No.  18, 
The  Modern  Spectroscope.  Ibid.,  May, 
1896,  Vol.  3,  pp.  321-347. 

Review  of  Langley's  Report  on  the  Smith- 
sonian Astrophysical  Observatory  for 

1895.  Ibid.,  May,  1896,  Vol.  3,  pp. 
398-401. 

The  Objective  Spectroscope.  No.  19,  The 
Modern   Spectroscope.      Ibid.,   June, 

1896,  Vol.  4,  pp.  54-78. 

Review  of  Professor  Stoney's  paper  on  the 
Equipment  of  the  Astrophysical  Ob- 
servatory of  the  Future.  Ibid.,  Oct., 
1896,  Vol.  4,  pp.  238-243. 

A  Note  on  the  Preparation  of  Phosphores- 
cent Barium  Sulphide.  Ibid.,  Nov., 
1896,  Vol.  4,  pp.  308-309. 

A  Note  on  a  Combined  Equatorial  Tele- 
scope and  Polar  Heliostat.   Ibid. ,  Nov., 

1896,  Vol.  4,  p.  310. 

On  a  New  Form  of  Mounting  for  Reflect- 
ing Telescopes,  devised  by  the  late 
Arthur  Cowper  Ranyard.    Ibid.,  Feb., 

1897,  Vol.  5,  pp.  132-142. 

A  Note  on  a  New  Form  of  Fluid  Prism. 
Ibid.,  Feb.,  1897,  Vol.  5,  p.  149. 

On  the  Resolving  Power  of  Telescopes 
and  Spectroscopes  for  Lines  of  Finite 
Width.  Memorie  della  Societa  degli 
Spettroscopisti  Italiani,  Jan.,  1897, 
Vol.  26,  pp.  2-22.  Philosophical  Maga- 
zine, May,  1897,  Vol.  43,  pp.  317-343. 

Thermal  Measurements  with  the  Bolo- 
meter by  the  Zero  Method.  Astro- 
physical  Journal,  April,  1897,  Vol.  5, 
pp. 268-276. 

The  Application  of  the  Interferometer  to 
the  Measurement  of  Small  Angular 
Deflections  of  a  Suspended  System. 
Physical  Revieio,  May-June,  1897, 
Vol.  4,  pp.  480-497. 

Tables  of  the  Practical  Resolving  Power 


of  Spectroscopes.  Astrophysical  Jour- 
nal, June,  1897,  Vol.  6,  pp.  27-36. 

Ueber  das  Auflosungsvermogen  von  Fern- 
rohren  und  Spectroskopen  fiir  Linien 
von  endlicher  Breite.  Ann.  der  Physik 
u.  Chemie,  June,  1897,  Vol.  61,  pp. 
004-630. 

On  the  Conditions  which  determine  the 
Limiting  Time  of  Exposure  of  Photo- 
graphic Plates  in  Astronomical  Pho- 
tography. Astronomische  Nachrichten, 
Vol.  144,  pp.  97-110. 

The  Effect  of  the  General  Illumination  of 
the  Sky  on  the  Brightness  of  the 
Field  at  the  Focus  of  a  Telescope. 
Monthly  Notices  of  Eoyal  Astronomical 
Soc,  June,  1897,  Vol.  57,  pp.  586-589. 

A  Note  on  Spider  Lines.  Ibid. ,  pp.  589- 
591. 

On  the  Conditions  which  determine  the 
Ultimate  Optical  Efficiency  of  Methods 
for  observing  Small  Rotations,  and  on 
a  Simple  Method  of  doubling  the  Ac- 
ciuracy  of  the  Mirror  and  Scale  Method, 
Philosophical  Magazine,  July,  1897, 
Vol.  44,  pp.  83-97. 

On  the  Conditions  of  Maximum  Efficiency 
in  Astrophilographic  Work.  Part  I. 
General  Theory  of  Telescopic  Images 
of  Different  Forms  of  Radiating 
Sources.  Astrophysical  Journal,  Aug., 
1897,  Vol.  6,  pp.  119-135. 

A  Comparison  of  the  Photographic  and 
of  the  Hand  and  Eye  Methods  of  de- 
lineating the  Surface  Markings  of 
Celestial  Objects.  Popular  Astron- 
omy, Aug.,  1897,  Vol.  5,  pp.  200-206. 

Astronomical  Photography.  Enoioledge, 
Aug.  and  Sept.,  1897,  Vol.  20,  pp.  193- 
195,  218-221. 

A  Note  on  the  Effect  of  Heat  on  Phos- 
phorescence. Astrophysical  Journal, 
Aug.,  1897,  Vol.  6,  pp.  153-155. 

Adam  Hilger.     Ibid.,  pp.  139-141. 

Review  of  Dr.  Braim's  Die  Gravitations 
Constante  die  Masse  und  mittlere 
Dichte  der  Erde.    Ibid.,  pp.  157-163. 

Sur  le  Pouvoir  S^parateur  des  Lunettes  et 
de  Spectroscopes  pour  les  Raies  de 
Largeur  Finie.  Jour,  de  Physique, 
Aug.,  1897,  Vol.  6,  pp.  409. 


Published  Pampers. 


555 


A  Determination  of  the  Specific  Resist- 
ance and  Temperature  Coefficient  of 
Oil  in  Tliin  Tilms  and  tlie  Application 
of  these  Results  to  the  Measurement 
of  the  Thickness  of  Oil  Films  in  Jour- 
nal Bearings.  Physical  Review^  Aug., 
1897,  Vol.  5,  pp.  75-97. 

On  the  Photography  of  Planetary  Sur- 
faces. Observatory,  Sept.,  Oct.,  Nov., 
1897,  Vol.  20,  pp.  333-341,  365-370, 
404-410. 

On  the  Conditions  required  for  attaining 
Maximum  Accuracy  in  the  Determina- 
tion of  Specific  Heat  by  the  Method  of 
Mixtures.  Am.  Jour,  of  Sci.,  Sept., 
1897,  Vol.  4,  pp.  265-282. 

On  the  Effect  of  the  Size  of  an  Objective 
on  the  Visibility  of  Linear  Markings 
on  the  Planets.  Astronomical  Jour- 
nal, Oct.  6,  1897,  Vol.  18,  pp.  41- 
45. 

On  the  Reduction  of  Observations.  Ob- 
servatory, Oct.  1897,  Vol.  20,  pp.  390- 
392. 

Note  on  the  General  Theory  of  Telescopic 
Images.    Astrophy steal  Journal,  Dec, 

1897,  Vol.  6,  p.  463. 

On  the  Theory  of  Lubrication  and  the 
Determination  of  the  Thickness  of  the 
Film  of  Oil  in  Journal  Bearings.  Jour, 
of  Franklin  Institute,  Dec,  1897,  Jan., 

1898,  Vols.  144-145. 

On  the  Conditions  of  Maximum  Efficiency 
in  Astrophilographic  Work.  Part  II. 
Effect  of  Atmospheric  Aberration  on 
the  Intensity  of  Telescopic  Images. 
Astrophysical  Journal,  Jan.,  1898, 
Vol.   7,  pp.  70-76. 

A  Note  on  the  Discovery  of  an  Error  in 
the  Papers  of  Struve  and  Lord  Ray- 
leigh  dealing  vpith  the  Application  of 
the  Principles  of  the  Wave  Theory  to 
the  Determination  of  the  Intensity  of 
the  Images  of  Fine  Lines  and  Ex- 
tended Areas  at  the  Focus  of  a  Tele- 
scope. Astrophysical  Journal,  Jan., 
1898,  Vol.  7,  pp.  77-85. 

A  Note  on  an  Error  in  the  Expression  for 
the  Intensity  of  Illumination  at  the 
Focal  Plane  of  a  Telescope  due  to  an 
Infinitely  Extended  Luminous  Area. 


Astronomical  Journal,  Jan.,  1898,  Vol. 
18,  pp.  124-126. 

A  Note  on  a  New  Form  of  Mirror  for  Re- 
flecting Telescopes.  Popular  Astron- 
omy, Feb.,  1898,  Vol.  5,  pp.  618-524. 

On  the  "  Worthlessness  "  of  Methods  of 
Geometrical  Optics  in  dealing  with  the 
Problems  relating  to  the  Definitive 
and  the  Delineating  and  Resolving 
Power  of  Telescopes.  Ibid.,  pp.  528- 
536. 

A  Note  on  the  Figuring  and  Use  of 
Eccentric  and  Unsymmetrical  Forms 
of  Parabolic  Mirrors.  Astrophysical 
Journal,  Feb.,  1898,  Vol.  7,  pp.  146- 
149. 

A  Note  on  the  Result  concerning  Dif- 
fraction Phenomena  recently  criticised 
by  Mr.  Newall.  Monthly  Notices  of 
Boyal  Astronomical  Soc,  March,  1898, 
Vol.  68,  pp.  286-291. 

Notes  on  the  Use  of  the  Grating  in  Stellar 
Spectroscopic  Work.  Astrophysical 
Joimial,  March,  1898,  Vol.  7,  pp.  198- 
208. 

CHARLES   "WALKER:  — 

B.C.E.,  University  of  Tennessee,  1885; 
M.A.,  ibid.,  1886;  Assistant  Professor 
of  Chemistry  and  Physics,  ibid.,  1886- 
88  ;  Assistant  in  Chemistry,  U.  S.  Naval 
Academy,  Annapolis,  1889-90 ;  Fellow 
in  Chemistry,  Clark  University,  1890- 
93  ;  Professor  of  Chemistry  and  Physics, 
Wisconsin  State  Normal  School,  1893-94 ; 
Professor  of  Natural  Science,  Carson- 
Newman  College,  Mossy  Creek,  Tenn. , 
1898-. 

Author  of :  — 

Oxidation  of  Meta-Brom  Toluene  and  Ni- 
trotoluene  Sulphamide.  (With  Dr. 
W.  A.  Noyes.)  Am.  Chem.  Jour., 
June,  1886, Vol.  8,  pp.  185-190. 

Oxidation  of  Para-xylene  Sulphamide. 
(With  Dr.  W.  A.  Noyes.)  Ibid., 
April,  1887,  Vol.  9,  pp.  93-99. 

The  Condensation-Products  of  Acetacetic- 
ether  Hydrazide  and  Oxalciticether 
Hydrazide.  Ibid.,  Dec,  1892,  Vol. 
14,  pp.  576-686. 


556 


Titles  of 


The  Condensation-Products  of  Aromatic 
Hydrazydes  of  Acetaciticether.  Indol 
and  Pyrazol  Derivations.  Ibid. ,  June, 
1894,  Vol.  16,  pp.  430-442. 

On  the  Action  of  Potassium  Hydroxide 
on  Orthomethoxysulphaminebenzoic 
Acid.  Ihid.,  1897,  Vol.  19,  pp.  578- 
580. 

ARTHUR   J.    WARNER:  — 

A.B.,  Marietta  College  O.,  1889;  A. 
M.,  ibid.,  1S97 ;  Scholar  in  Physics, 
Clark  University,  1889-90  ;  Engaged  in 
Electrical  Work,  Johns  Hopkins  Univer- 
sity, 1890-92 ;  Certificate  in  Electrical 
Engineering,  ibid..,  1892  ;  With  the  Cher- 
okee Mining  Co.,  Chute,  Ga.,  1898-. 

SHO    "WATASE  :  — 

B.S.,  Sapporo,  Japan,  1884;  Student  of 
Zoology,  University  of  Tokio,  1884-86; 
Eellow  in  Biology,  Johns  Hopkins  Univer- 
sity, 1888-89 ;  Bruce  Fellow,  ibid.,  1889- 
90 ;  Ph.D.,  Johns  Hopkins  University, 
1890  ;  Lecturer  and  Assistant  in  Mor- 
phology, Clark  University,  1890-92  ; 
Eeader  in  Cellular  Biologj",  University 
of  Chicago,  1892-93  ;  Instructor  in  Anat- 
omy and  Physiology  of  the  Cell,  ibid., 
1893-95 ;  Assistant  Professor  in  Cellular 
Biology,  ibid.,  189^5-99 ;  Professor  of 
Cellular  Biologj',  Imperial  University, 
Tokio,  Japan,  1899-. 

Author  of :  — 

Caryokinesis  and  the  Cleavage  of  the 
Ovum.     J.   H.    U.    Circulars,   April, 

1890,  Vol.  9,  pp.  53-56. 

On  the  Morphology  of  the  Compound 
Eyes  of  Arthropods.  Quar.  Jour,  of 
Micr.  Sci.,  June,  1890,  N.  S.,  Vol.  31, 
pp.  143-158,  1  pi. 

On  Caryokinesis.  Woods  Hall  Biological 
Lectures,  1890.     Ginn  &  Co.,  Boston, 

1891,  pp.  168-187. 

Studies  on  Cephalopods.  I.  Cleavage  of 
the  Ovum.  Journal  of  Morphology, 
Jan.,  1891,  Vol.  4,  pp.  247-302,  4  pis. 

The  Origin  of  the  Sertoli's  Cell.  Ameri- 
can Naturalist,  May,  1892,  Vol.  26, 
pp.  442-444. 


On  the  Significance  of  Spermatogenesis. 
Ibid.,  July,  1892,  Vol.  26,  pp.  624-626. 

On  the  Phenomena  of  Sex  Differentiation. 
Jour,  of  Morph. ,  July,  1892,  Vol.  6,  pp. 
481-493. 

Homology  of  the  Ceutrosome.  Ibid., 
May,  1893,  Vol.  8,  pp.  433-444. 

On  the  Nature  of  Cell  Organization. 
Woods  Holl  Biological  Lectures,  1893. 
Ginn  &  Co.,  Boston,  1894,  pp.  83-103. 

Origin  of  the  Centrosome.  Ibid.,  1894. 
Ginn  &  Co.,  Boston,  1895,  pp.  273-287. 

On  the  Physical  Basis  of  Animal  Phos- 
phorescence. Ibid.,  1895.  Ginn  & 
Co.,  Boston,  1896,  pp.  101-118. 

Microsomes  and  their  Relation  to  the 
Centrosome.  Science,  Feb.  5,  1897, 
N.  S.,  Vol.  5,  pp.  230-231. 

Protoplasmic  Contractibility  and  Phos- 
phorescence.   /6zc?.,1898.    (In  press.) 

OLIVER   P.    WATTS:  — 

A.B.,  Bowdoin  College,  1889 ;  A.M., 
ibid.,  1892;  Scholar  in  Chemistry, 
Clark  University.  1889-90  ;  Instructor 
in  Physics,  Chemistry,  and  Mathematics, 
Franklin  Academy,  Malone,  N.  Y.,  1892- 
98  ;  Instructor  in  Physics,  High  School, 
Waltham,  Mass.,  1898-. 

ARTHUR  GORDON  WEBSTER:  — 
A.B.,  Harvard  University,  1885;  In- 
stn;ctor  in  Mathematics,  ibid.,  1885-86; 
Parker  Fellovr,  ibid.,  1886-89;  Student, 
Universities  of  Berlin,  Paris,  and  Stock- 
holm. 1886-90  ;  Ph.D.,  University  of  Ber- 
lin, 1890 ;  Docent  in  Physics.  Clark 
University,  1890-92  ;  Assistant  Pro- 
fessor of  Physics,  1892- ;  Resident 
Fellow,  American  Academy  of  Arts  and 
Sciences ;  Fellow,  American  Association 
for  the  Advancement  of  Science ;  Mem- 
ber :  American  Mathematical  Society, 
American  Physical  Society. 

Author  of :  — 

Versuche  liber  eine  Methode  zur  Bestim- 
mung  des  Verhaltnisses  der  elektro- 
magnetischen  zur  elektrostatischen 
E  in  he  it  der  Elektricitat.  (Inaugural- 
dissertation.)     Berlin,  1890. 


Published  Papers. 


557 


A  National  Physical  Laboratory.  Peda- 
gogical Seminary,  June,  1892,  Vol.  2, 
pp.  90-101. 

Unipolar  Induction  and.  Current  without 
Difference  of  Potential.  Electrical 
World,  April  14-21,  1894,  Vol.  23, 
pp.  491-492,  523-524. 

On  a  Means  of  producing  a  Constant  An- 
gular Velocity.  Am.  Jour,  of  Sci., 
May,  1897,  Vol.  3,  pp.  379-382. 

A  Rapid  Break  for  Large  Currents.  Ibid. , 
pp.  383-386. 

A  New  Instrument  for  measuring  the  In- 
tensity of  Sound.  (With  B.  F.  Sharpe. ) 
Beport  British  A.  A.  S.,  Toronto,  1897, 
p.  584.  Also  Proc.  A.  A.  A.  S.,  Bos- 
ton, 1898,  p.  136. 

The  Theory  of  Electricity  and  Magnetism, 
being  Lectures  on  Mathematical  Phys- 
ics. Macmillan  &  Co.,  London,  1897. 
563  pp. 

An  Experimental  Determination  of  the 
Period  of  Electrical  Oscillations. 
(Elihu  Thomson  Prize,  Paris,  1895.) 
Physical  Beview,  May-June,  1898, Vol. 
6,  pp.  297-314. 

Note  on  Stokes's  Theorem  in  Curvilinear 
Coordinates.  Bull.  Am'.  Math.  Soc, 
June,  1898,  2d  ser.,  Vol.  4,  pp.  438- 
441. 

A  New  Chronograph  and  a  Means  of 
Eating  Tuning-forks.  P^-oc.  A.  A.  A. 
S.,  Boston,  1898,  p.  136. 

A  Geometrical  Method  for  Investigating 
Diffraction   by   a   Circular   Aperture. 
Ibid.,  p.  136. 
Eeport  on  the  State  of  the  Mathematical 
Theory  of  Electricity  and  Magnetism. 
Ibid.,  pp.  103-112.    Also  Science,  Dec. 
9,  1898,  Vol.  8,  pp.  803-810. 
Ten  Lowell   Institute  Lectures  on  Elec- 
tricity and  Magnetism,  Light,  and  the 
Ether,  1897. 
Six  Lectures  for  the  Colloquium  of  the 
American  Mathematical  Society,  1898. 

JULIUS    B.    WEEMS:  — 

B.S.,  Maryland  Agricultural  College, 
1888  ;  Instructor  in  Chemistry  and  Mathe- 
matics, ibid.,  1888-89;  Student,  Johns 
Hopkins  University,  1889-91 ;  Chemist  at 


Phosphate  Mines,  Florida,  1891-92  ;  Fel- 
low in  Chemistry,  Clark  University, 
1892-94 ;     Ph.D.,    Clark    University, 

1894  ;  On  Special  Research  at  New  York 
Experiment  Station,  Geneva,  N.  Y.,  Oct., 
1894-March,  1895 ;  Professor  of  Agricul- 
tural Chemistry,  Iowa  State  College  of 
Agriculture  and  Mechanic  Arts,  and 
Chemist,  Iowa  Experiment  Station,  Ames, 
la.,  March,  [1895- ;  Chemist,  Iowa  Geo- 
logical Survey,  Jan.,  1899- ;  Member: 
German  Chemical  Society,  American 
Chemical  Society,  Society  of  Chemical 
Industry  of  London,  Society  for  Promo- 
tion of  Agricultural  Science,  American 
Academy  of  Political  and  Social  Science  ; 
Fellow,  Iowa  Academy  of  Science. 

Author  of :  — 

On  Electrosyntheses  by  the  Direct  Union 

of  Anions  of  Weak  Organic  Acids. 

Am.    Chem.   Jour.,   Dec,    1894,  Vol. 

16,  pp.  569-588. 
The  Chemical  Composition  of  Squirrel-tail 

Grass.       lov^a     Experiment     Station 

Bull,  No.  30,  pp.  320-321. 
Studies  on  Milk  Preservatives.     Ibid.,  No. 

32,  pp.  499-504. 
Soil  Moisture.     Ibid.,  No.  32,  pp.  505-515. 
The  Adulteration  of  Food.     Bep.  of  State 

Dairy  Com.  of  loim,  1895,  pp.  212-216. 
Soil  Moisture.     Iowa  Experiment  Station 

Bull.,  No.  36,  pp.  825-848. 
Milk  Preservatives.   III.  State  Dairyman' s 

Ass'n,  1898,  pp.  103-110. 
Chemistry  and  some  of  its  Relations  to 

Agriculture.     Bep.  of  the  Iowa  State 

Agric.  Soc,  1898,  pp.  42-48. 

GERALD   M.    "WEST:  — 

A.B.,  Columbia  College,  1888;  A.M., 
ibid.,  1889;  Ph.D.,  Columbia  College, 
1890  ;  Fellow  in  Anthropology,  Clark 
University,  1890-91 ;  Assistant  in 
Anthropology,  1891-92  ;  First  Assist- 
ant in  Anthropology,  Bureau  of  Ethnology, 
World's  Columbian  Exposition,  1892-93  ; 
Docent  in  Ethnology,  University  of 
Chicago,  1893-95 ;  Curator  of  Physical 
Anthropology,  Field  Columbian  Museum, 
Chicago,  1894. 


558 


Titles  of 


Author  of:  — 

The  Status  of  the  Negro  in  Virginia  during 
the  Colonial  Period.  (Thesis  for  the 
Doctorate.)     New  York,  1890.     76  pp. 

The  Growth  of  the  Breadth  of  the  Face. 
Science,  July  3,  1891,  Vol.  18,  pp.  10- 
11. 

Eye-Tests  on  School  Children.  Am.  Jour, 
of  Psy.,  Aug.,  1892,  Vol.  4,  pp.  695- 
596. 

The  Growth  of  the  Body,  Head,  and  Face. 
Science,  Jan.  6,  1893,  Vol.  21,  pp.  2-4. 

The  Anthropometry  of  American  School 
Children.  Mem.  Internat.  Congress  of 
Anthropology,  1893  (Chicago,  1894), 
pp.  50-58. 

Anthropometrische  Untersuchungen  iiber 
die  Schulkinder  in  Worcester,  Mass., 
Amerika.  Arch.  f.  Anthropologie, 
Braunschweig,  1893,  Vol.  22,  pp.  13-48. 

The  Growth  of  the  Human  Body,  Edu- 
cational Beview,  Oct.,  1896,  Vol.  12, 
pp.  284-289. 

Observations  on  the  Eelation  of  Physical 
Development  to  Intellectual  Ability, 
made  on  the  School  Children  of  To- 
ronto, Canada.  Science,  Aug.  7,  1896, 
N.  S.,  Vol.  4,  pp.  156-159. 

A.    HARRY   WHIEELER:  — 

S.B.,  Worcester  Polytechnic  Institute, 
1894  ;  Instructor  in  Mathematics,  English 
High  School,  Worcester,  1894-Dec.,  1896; 
and  1899- ;  Scholar  in  Mathematics, 
Clark  University  Dec,  1896-June, 
1899. 

WILLIAM   MORTON   WHEELER:  — 

Graduate,  German  and  English  Academy, 
Milwaukee, Wis.,  1880 ;  Graduate  German- 
American  Normal  College,  Milwaukee, 
Wis.,  1883;  Ward's  Natural  Science  Es- 
tablishment, Rochester,  N.  Y.,  1883-85; 
Teacher  of  German  and  Assistant  in  Biol- 
ogy, Milwaukee  Public  High  School,  1885- 
88 ;  Curator,  Milwaukee  Public  Museum, 
1887-90;  Fellow  and  Assistant  in 
Morphology,  Clark  University,  1890- 
92;  Ph.D.,  Clark  University,  1892; 
Student  at  the  University  of  Wurzburg 
and  University  of  Li^ge ;  Occupant  of  the 


Smithsonian  Table  at  the  Zoological  Sta- 
tion, Naples,  1893-94;  Instructor  in  Em- 
bryology, University  of  Chicago,  1892-95 ; 
Assistant  Professor  of  Embryology,  ibid., 
1895-99 ;  Professor  of  Zoology,  University 
of  Texas,  1899. 

Author  of :  — 

Spiders  of  the  Sub-family  Lyssomanae. 
(With  G.  W.  and  E.  G.  Peckham.) 
Trans.  Wis.  Acad.  Science,  Arts  and 
Letters,  Vol.  7,  1888,  pp.  222-256,  Pis. 
xi.  and  xii. 

On  Two  New  Species  of  Cecidomyid  Flies 
producing  Galls  on  Antennaria  planta- 
ginifolia.  Proc.  Wis.  Nat.  Hist.  Soc, 
April,  1889,  pp.  209-216. 

Two  Cases  of  Insect  Mimicry.  Ibid.,  pp. 
217-221. 

Ueber  drtisenartige  Gebilde  im  ersten  Ab- 
dominal-segment der  Hemipterenem- 
bryonen.  Zool.  Anzeiger,  1889,  12 
Jahrg.,  pp.  500-504,  2  fig. 

Homologues  in  Embryo  Hemiptera  of  the 
Appendages  to  the  First  Abdominal 
Segment  of  other  Insects.  Amej'ican 
Naturalist,  1889,  pp.  644-645. 

The  Embryology  of  Blatta  germanica  and 
Doryphora  decem-lineata.  Jo^tr.  of 
llorph.,  Sept.,  1889,  Vol.  3,  pp.  291- 
386,  7  pi. 

On  the  Appendages  of  the  First  Abdomi- 
nal Segment  of  Embryo  Insects.  Wis. 
Acad.  Science,  Arts  and  Letters,  Sept. 
20,  1890,  Vol.  8,  pp.  87-140,  Pis.  i.- 
iii. 

Ueber  ein  eigenthiimliches  Organ  im  Lo- 
custidenembryo.  Zool.  Anzeiger,  13 
Jahrg.,  1890. 

Note  on  the  Oviposition  and  Embryonic 
Development  of  Xiphidium  ensiferum 
Scud.  Insect  Life,  1890,  Vol.  2,  pp. 
222-225. 

Descriptions  of  Some  New  North  American 
Dolichopodidae.  Psyche,  1890,  Vol.  1, 
pp.  337-343,  356-362,  373-379. 

The  Supposed  Bot-fly  Parasite  of  the  Box- 
Turtle.     Ibid.,  1890,  Vol.  1,  p.  403. 

Hydrocyanic  Acid  secreted  by  Polydesmus 
virginiensis  Drury.    /6td.,  1890,  Vol.  1,  ■ 
p.  442. 


Published  Papers. 


559 


The  Embryology  of  a  Common  Fly.  Ihid., 
1891,  Vol.  2,  pp.  97-99. 

The  Germ-band  of  Insects.  Ihid.,  1891, 
Vol.  2,  pp.  112-115. 

Neuroblasts  in  the  Arthropod  Embryo. 
Jorir.  of  Morph.,  Jan.,  1891,  Vol.  4,  pp. 
337-343,  1  fig. 

Concerning  the  "  Blood-tissue  "  of  the  In- 
secta.  Ibid. ,  1892,  Vol.  2,  pp.  216-220, 
233-236,  253-258,  PI.  vii. 

A  Contribution  to  Insect  Embryology. 
(Inaugural  Dissertation.)  Jour,  of 
Morph.,  April,  1893,  Vol.  8,  pp.  1-160, 
6  pis. 

The  Primitive  Number  of  Malpighian  Ves- 
sels in  Insects.  Psyche,  1893,  Vol.  2, 
pp.  457-460,  485-486,  497-498,  509-510, 
539-541,  545-547,  561-564,  2  figs. 

Synccelidium  pellucidum,  a  New  Marine 
Triclad.  Jorir.  of3Iorph.,  April,  1894, 
Vol.  9,  pp.  167-194,  1  pi. 

Planocera  inquilina,  a  Polyclad  inhabiting 
the  Branchial  Chamber  of  Sycotypus 
canaliculatus  Gill.  Ibid.,  April,  1894, 
Vol.  9,  pp.  195-201,  2  figs. 

Protandric  Hermaphroditism  in  Myzo- 
stoma.  Zool.  Anzeiger,  17  Jahrg., 
1894. 

The  Behavior  of  the  Centrosomes  in  the 
Fertilized  Egg  of  Myzostoma  glabrum 
Leuckart.  Jour,  of  Morph.,  Jan., 
1895,  Vol.  10,  pp.  305-311. 

The  Problems,  Methods,  and  Scope  of 
Developmental  Mechanics.  (Trans- 
lated from  the  German  of  Wilhelm 
Roux.)  Biological  Lectures,  Marine 
Biological  Laboratory,  Woods  Holl, 
1895,  pp.  149-190. 

The  Sexual  Phases  of  Myzostoma.  Mitth. 
a.  d.  Zool.  Station  zxi  JSfeapel,  1896, 
Vol.  12,  pp.  227-302.     Pis.  x.-xii. 

The  Genus  Ochthera.  Entomological 
News,  April,  1896,  Vol.  7,  pp.  121- 
123,  1  fig. 

Two  Dolichopodid  Genera  New  to  Amer- 
ica. Ibid.,  May,  1896,  Vol.  7,  pp.  152- 
156. 

A  New  Genus  and  Species  of  Dolicho- 
podidfe.  Ibid.,  June,  1896,  Vol.  7, 
pp.  185-189,  1  fig. 

A  New  Empid  with  Remarkable  Middle 


Tarsi.     Ibid.,  June,  1896,  Vol.  7,  pp. 
189-192,  3  figs. 

An  Antenniform  Extra  Appendage  in 
Dilophus  tibialis  Loew.  Arch.  f.  Ent- 
wick.  Mech.  d.  Organismen,  1896,  Vol. 
3,  pp.  261-268,  PI.  xvi. 

The  Maturation,  Fecundation,  and  Early 
Cleavage  of  Myzostoma  glabrum 
Leuckart.  Arch,  de  Biologic,  1897, 
Vol.  15,  pp.  1-77,  Pis.  i.-iii. 

A  Genus  of  Maritime  Dolichopodidae  New 
to  America.  Proc.  Cal.  Acad.  Sci., 
Zool,  July,  1897,  3d  ser.,  Vol.  1,  pp. 
145-152.  PI.  iv. 

A  New  Genus  of  Dolichopodidse  from 
Florida.  Zoological  Bulletin,  Feb., 
1898,  Vol.  1,  pp.  217-220,  1  fig. 

A  New  Peripatus  from  Mexico.  Jour,  of 
Morph.,  Oct.,  1898,  Vol.  15,  pp.  1-8, 1  pi. 

George  Baur's  Life  and  Writings.  Amer- 
ican Naturalist,  Jan.,  1899,  Vol.  33, 
pp.  15-30. 

Anemotropism  and  Other  Tropisms  in 
Insects.  Arch.  f.  Entwick.  3Iech.  d. 
Organismen,  1899,  Vol.  8,  pp.  373-381. 
New  Species  of  Dolichopodidse  from  the 
United  States.  Proc.  Cal.  Acad.  Set, 
Zool.,  3d  ser,  Sept.,  1899,  Vol.  2,  pp. 
1-77,  Pis.  i.-iv. 

The  Development  of  the  Urinogenital  Or- 
gans of  the  Lamprey.  Zool.  Jahr- 
hucher,  Ahth.  f.  Morph.,  1899,  Bd.  13, 
pp.  1-88,  Pis.  i.-vii. 

The  Life-History  of  Dicyema.  Zool.  An- 
zeig.,  April,  1899,  Vol.  22,  pp.  169-176. 

J.  Beard  on  the  Sexual  Phases  of  Myzos- 
toma. Ibid.,  July,  1899,  Vol.  22,  pp. 
281-288. 

Caspar  Friedrich  Wolff  and  the  Theoria 
Generationis.  Biological  Lectures, 
Marine  Biological  Laboratory,  Woods 
Holl,  1899. 

GUY   MONTROSE   WHIPPLE:  — 

A.B. ,  Brown  University,  1897  ;  Scholar 
and  Assistant  in  Psychology,  Clark 
University,  1897-98  ;  Assistant  in  Psy- 
chology, Cornell  University,  1898-. 

Author  of :  — 

The  Influence  of  Forced  Respiration  on 
Psychical  and  Physical  Activity.     Am. 


560 


Titles  of 


Jour,  of  Psy.,  July,  1898,  Vol.  9,  pp. 
660-571. 
On     Nearly     Simultaneous     Clicks     and 
Flashes.     Ibid.,  Jan.,   1899,   Vol.    10, 
pp.  280-286. 

HENRY    S.   WHITE  :  — 

A.B.,  Wesleyan  University,  1882 ;  Assistant 
in  Astronomy  and  Physics,  ibid.,  1882-83  ; 
Instructor  in  Mathematics,  Hackettstown, 
N.  J.,  1883-81  ;  Tutor  in  Mathematics, 
Wesleyan  University,  1884-87;  Ph.D., 
University  of  Gottingen,  1890  ;  Assistant 
in  Mathematics,  Clark  University, 
1890-92  ;  Associate  Professor  of  Mathe- 
matics, Northwestern  University,  1892-94 ; 
Noyes  Professor  of  Pure  Mathematics, 
ibid.,  1894- ;  Member  American  Mathe- 
matical Society. 

Author  of :  — 

Ueber  zwei  covariante  Formen  aus  der 
Theorie  der  Abel'schen  Integrale 
auf  voUstandigen,  singularitatenfreien 
Schnittcurven  zweier  Flachen.  Math. 
Annalen,  1890,  Vol.  36,  pp.  597-601. 

Abel'sche  Integrale  auf  singularitaten- 
freien, einfach  uberdeckten,  voUstan- 
digen Schnittcurven  eines  beliebig 
ausgedehnten  Raumes.  Nova  Acta 
Leop.-Carol.  Akad.,  1891,  Vol.  57,  pp. 
41-128. 

On  generating  Systems  of  Ternary  and 
Quaternary  Linear  Transformations. 
Am.  Jour,  of  Math.,  July,  1892,  Vol. 
14,  pp.  274-282. 

A  Symbolic  Demonstration  of  Hilbert's 
Method  for  deriving  Invariants  and 
Covariants  of  Given  Ternary  Forms. 
Ibid.,  pp.  283-290. 

Revievsr  of  Klein's  Evanston  Lectures. 
Bull.  K  T.  Math.  Soc,  Feb.  1894, 
Vol.  3,  pp.  119-122. 

Reduction  of  the  Resultant  of  a  Binary 
Quadric  and  n-ic  by  Virtue  of  its  Semi- 
combinant  Property.  Ibid. ,  Oct.,  1894, 
Vol.  1,  pp.  11-15. 

Semi-combinants  as  Concomitants  of  Af- 
filiants.  Am.  Jour,  of  Math.,  July, 
1895,  Vol.  17,  pp.  235-265. 

Kronecker's  Linear  Relation  among  Minors 


of  a   Symmetric  Determinant.     Bull. 

Am.   Math.   Soc,  Feb.,   1896,  Vol.  2, 

pp.  136-138. 
Numerically  Regular  Reticulations  upon 

Surfaces  of  Deficiency  higher  than  1. 

Ibid.,   Dec,    1896,    Vol.    3,    pp.    116- 

121. 
The  Cubic  Resolvent  of  a  Binary  Quartic 

Derived  by  Invariant  Definition  and 

Process.    Ibid.,   April,    1897,  Vol.  3, 

pp.  250-253. 
CoUineations  in  a  Plane  with  Invariant 

Quadric  or  Cubic  Curves.     Ibid.,  Oct., 

1897,  Vol.  4,  pp.  17-23. 
Inflexional  Lines,  Triplets,  and  Triangles 

associated  with  the  Plane  Cubic  Curve. 
Ibid.,  March,  1898,  Vol.  4,  pp.  258- 
260. 

The  Construction  of  Special  Regular  Re- 
ticulations on  a  Closed  Surface.  Ibid. , 
May,  1898,  Vol.  4,  pp.  376-382. 

Elliott's  Algebra  of  Quantics.  Review. 
Ibid.,  July,  1898,  Vol.  4,  pp.  545-549. 

The  Cambridge  Colloquium.     Ibid.,  Oct., 

1898,  Vol.  5,  pp.  57-58. 

Report  on  the  Theory  of  Projective  Inva- 
riants ;  the  Chief  Contributions  of  a 
Decade.  Ibid.,  Jan.,  1899,  Vol.  5,  pp. 
161-175. 

CHARLES   O.  WHITMAN:  — 

A.B.,  Bowdoin  College,  1868;  Principal 
Westford  Academy  and  Master  in  the 
English  High  School,  Boston,  1869-75 ; 
Ph.D.,  University  of  Leipzig,  1878  ;  Fel- 
low, Johns  Hopkins  University,  1878-79  ; 
Professor  of  Zoology,  Imperial  University 
of  Japan,  1880-81 ;  Naples  Zoological 
Station,  1881-82  ;  Director,  AUis  Lake 
Laboratory,  1886-89 ;  Director,  Marine 
Biological  Laboratory,  Woods  Holl,  Mass., 
1888- ;  Professor  of  Animal  Morphol- 
ogy, Clark  University,  1889-92  ;  Head 
Professor  of  Zoology,  University  of 
Chicago,  1892- ;  Editor  of :  Journal  of 
Morphology,  1887-  ;  Biological  Lectures 
from  the  Marine  Biological  Laboratory, 
Woods  Holl,  Mass.,  1890- ;  American 
Naturalist,  Department  of  Microscopy, 
1883-96  ;  Zoological  Bulletin,  1897-99 
(continued  in  Biological  Bulletin,  1899-). 


Published  Papers. 


561 


Author  of :  — 

The  Embryology  of  Clepsine.  Quar. 
Jour.  Micr.  Sci.,  1878,  Vol.  18,  pp. 
215-315. 

Ueber  die  Embryologie  von  Clepsine. 
Zool.  Anzeiger,  1878,  Vol.  1,  pp.  5-6. 

Changes  Preliminary  to  Cleavage.  Proc. 
A.  A.  A.  S.,  1878,  Vol.  27,  pp.  263- 
270. 

Do  Flying  Fish  Fly  ?  Ame7'ican  Natural- 
ist, Sept.,  1880,  Vol.  14,  pp.  641-653. 

Zoology  in  the  University  of  Tokio,  Yoko- 
hama, 1881,  pp.  1-44. 

Methods  of  Microscopical  Research  in  the 
Zoological  Station  of  Naples.  Ameri- 
can Naturalist,  Sept.,  1882,  Vol.  16, 
pp.  697-785. 

A  New  Species  of  Branchiobdella.  Zool. 
Anzeiger,  Sept.  10, 1882,  Vol.  5,  pp.  1-2. 

The  Advantages  of  Study  at  the  Naples 
Zoological  Station.  Science.,  July  27, 
1883,  Vol.  2,  pp.  93-97. 

A  Rare  Form  of  the  Blastoderm  of  the 
Chick,  and  its  Bearing  on  the  Question 
of  the  Formation  of  the  Vertebrate 
Embryo.       Q%iar.    Jour.   Micr.    Sci., 

1883,  Vol.  23,  pp.  375-397. 

A  Contribution  to  the  Embi-yology,  Life- 
History,  and  Classification  of  the  Di- 
cyemids.  Mitth.  azis  d.  Zool.  Station 
von  Neapel,  Jan.  23,  1883,  Vol.  4,  pp. 
1-89,  5  pis. 

On  the  Development  of  some  Pelagic  Fish 
Eggs.  (With  Alexander  Agassiz.) 
Proc.  Am.  Acad.  Arts  and  Sciences, 

1884,  N.  S.,  Vol.  12,  pp.  23-75. 

The  External  Morphology  of  the  Leech. 

(With    Alexander    Agassiz.)       Ibid., 

1884,  N.  S.,  Vol.  12,  pp.  76-87. 
The  Connective  Substance  in  the  Hiru- 

dinea.      American    Naturalist,    Oct., 

1884,  Vol.  18,  pp.  1070-1071. 
The     Segmental     Sense-Organs    of    the 

Leech.      Ibid.,   Nov.,    1884,   Vol.    18, 

pp.  1104-1109. 
The    Pelagic    Stages    of    Young    Fishes. 

(With    Alexander    Agassiz.)       Mem. 

Mus.   Comp.  Zoology,  1885,  Vol.  14, 

pp.  1-56. 
Methods  in  Microscopical  Anatomy  and 

Embryology.     Boston,  1885.     255  pp. 
2o 


The  Germ-Layers  of  Clepsine.  Zool. 
Anzeiger,  1886,  Vol.  1,  pp.  1-6. 

The  Leeches  of  Japan.  Qiiar.  Jour. 
Micr.  Sci.,  April,  1886,  Vol.  26,  pp. 
317-416.     5  pis. 

Biological  Instruction  in  Universities. 
American  Naturalist,  June,  1887,  Vol. 
21,  pp.  507-519. 

A  Contribution  to  the  History  of  the 
Germ-Layers  in  Clepsine.  Jour,  of 
Morph.,  Sept.,  1887,  Vol.  1,  pp.  105- 
182,  3  pis. 

The  Kinetic  Phenomena  of  the  Egg 
during  Maturation  and  Fecundation. 
Ibid.,  Dec,  1887,  Vol.  1,  pp.  227- 
252. 

The  Seat  of  Formative  and  Regenerative 
Energy.  Ibid.,  July,  1888,  Vol.  2, 
pp.  27-49. 

Address  at  the  opening  of  the  Marine 
Biological  Laboratory,  July  17,  1888. 
First  Annual  Beport  for  the  Year 
1888,  pp.  24-31. 

The  Development  of  Osseous  Fishes. 
(With  Alexander  Agassiz.)  II.  The 
Preembryonic  Stages  of  Development. 
Part  I.  The  History  of  the  Egg  from 
Fertilization  to  Cleavage.  3Iem.  Mus. 
Comp.  Zoology,  1889,  Vol.  14,  pp. 
1-40. 

Some  New  Facts  about  the  Hirudinea. 
Jour,  of  Morph.,  April,  1889,  Vol.  2, 
pp.  586-599. 

Specialization  and  Organization,  Compan- 
ion Principles  of  all  Progress.  The 
Most  Important  need  of  American  Bi- 
ology. Woods  Holl  Biological  Lec- 
tures, 1890.  Ginn  &  Co.,  Boston,  1891, 
pp.  1-26. 

The  Naturalist's  Occupation.  Ibid.,  1890. 
Ginn  &  Co.,  Boston,  1891,  pp.  27-52. 

Spermatophores  as  a  Means  of  Hypoder- 
mic Impregnation.  Jour,  of  Morph., 
Jan.,  1891,  Vol.  4,  pp.  361-406,  1  pi. 

Description  of  Clepsine  Plana.  Ibid.,  pp. 
407-418,  1  pi. 

Metamerism  of  Clepsine.  LeuckarVs 
Festschrift,  1892,  pp.  385-395. 

The  Marine  Biological  Laboratory,  Fri- 
day Chapel  Address.  University  News, 
Chicago,  Dec.  17^  1892. 


562 


Titles  of 


General  Physiology  and  its  Relations  to 
Morphology.  Fifth  Annual  Report 
Marine  Biological  Laboratory,  1892. 
Reprinted  in  American  Naturalist, 
Sept.,  1893,  Vol.  27,  pp.  802-807. 

A  Marine  Biological  Observatory.  Fop. 
Sci.  Mo.,  Feb.,  1893,  Vol.  42,  pp.  459- 
471. 
A  Marine  Observatory  the  Prime  Need  of 
American  Biology.  Atlantic  Monthly, 
June,  1893,  Vol.  71,  pp.  808-815. 

A  Sketch  of  the  Structure  and  Develop- 
ment of  the  Eye  of  Clepsine.  Spen- 
geVs  Zool.  Jahrbilcher,  1893,  Vol.  6, 
pp.  616-625. 

The  Inadequacy  of  the  Cell-Theory  of  De- 
velopment.    Jour,  of  Morph.,  August, 

1893,  Vol.  8,  pp.  639-658  ;  also  Woods 
Holl  Biological  Lectures,  1893.  Ginn 
&  Co.,  Boston,  1894,  pp.  105-124. 

The  Work  and  the  Aims  of  the  Marine 
Biological  Laboratory.  Woods  Holl 
Biological  Lectures,  1893.  Ginn  & 
Co.,  Boston,  1894,  pp.  235-242. 

Evolution  and  Epigenesis.  Ibid.,  1894. 
Ginn  &  Co.,  1895,  pp.  205-224. 

Bonnet's    Theory  of    Evolution.     Ibid., 

1894,  Gmn  &  Co.,  1895,  pp.  225-240. 
The  Palingenesia  and  the  Germ  Doctrine 

of  Bonnet.     Ibid.,  189i,     Ginn  «&  Co., 

1895,  pp.  241-272. 

The  Egg  of  Amia  and  its  Cleavage.  (With 
A.  C.  Eycleshymer.)  Joiir.  of  Morph., 
Feb.,  1897,  Vol.  12,  pp.  309-354.  2 
pis. 

Some  of  the  Functions  and  Features  of  a 
Biological  Station.  Presidential  Ad- 
dress to  the  Society  of  American  Nat 
uralists,  Ithaca  meeting,  1897.  Woods 
Holl  Biological  Lectrires,  1896-97 
Ginn  &  Co.,  Boston,  1898,  pp.  231- 
242 ;  also  in  Science,  Jan.  14,  1898 
Vol.  7,  pp.  37-44. 

The  Centrosome  Problem  and  an  Experi 
mental  Test.  Science,  Feb.  5,  1897 
N.  S.,  Vol.  5,  p.  67. 

Lamarck  and  "A  Perfecting  Tendency.' 
Ibid.,  Jan.  21,  1898,  Vol.  7,  p.  99. 

Apathy's  Grief  and  Consolation.  Zool 
Anzeiger,  May  1,  1899,  Vol.  22,  pp 
196-197. 


Myths  in  Animal  Psychology.  Monist, 
July,  1899,  Vol.  9,  pp.  524-537. 

Animal  Behavior.  Woods  Holl  Biologi- 
cal Lectures,  1898,  pp.  285-338. 

FRANK   B.  WILLIAMS:  — 

C.E.,  Missouri  State  University,  1890  ; 
M.S.,  ibid.,  1893;  Teaching  Fellow  in 
Mathematics,  ibid.,  1892-93;  United 
States  Assistant  Engineer,  Tennessee 
River  Improvement,  1895-97  ;  Scholar 
in  Mathematics,  Clark  University, 
1897-98  ;  FeUow,  1898-99. 

Author  of :  — 

Note  on  the  Finite  Continuous  Groups  of 
the  Plane.  Froc.  Am.  Acad,  of  Arts 
and  Sci.,  Nov.,  1899,  Vol.  35,  pp. 
97-107. 

J.  FRANCIS   WILLIAMS:  — 

C.E.,  Rensselaer  Polytechnic  Institute, 
1883  ;  B.S.,  ibid.,  1884  ;  Ph.D.,  Univer- 
sity of  Gottingen,  1886 ;  University  of 
Berlin,  1887  ;  Director,  Technical  Museum 
of  Pratt  Institute,  Brooklyn,  N.  Y.,  1887- 
89  ;  Decent  in  Mineralogy,  Clark  Uni- 
versity, 1889-90 ;  Assistant  Professor 
of  Geology,  Cornell  University,  1890-91. 
Died  Nov.  9,  1891, 

Author  of:  — 

Tests  of  Rutland  and  Washington  County 
Slates.  Van  NostrancVs  Eng.  Mag., 
1884,  No.  188. 

Ueber  den  Monte  Amiata  in  Toscana  und 
seine  Gesteine.  Stuttgart,  1887. 

Igneous  Rocks  of  Arkansas.  Annual  Re- 
port of  the  Geological  Survey,  Arkan- 
sas, 1890,  Vol.  2.     457  pp.    Illustrated. 

ALBERT   P.  WILLS:  — 

B.E.E.,  Tufts  College  (with  Honors  in 
Electricity),  1894  ;  Scholar  in  Physics, 
Clark  University,  1894-95  ;  Fellovir, 
1895-Jan.,  1897;  Ph.D.,  Clark  Uni- 
versity, 1897  ;  Professor  of  Physical 
Sciences,  Colorado  State  Normal  School, 
Jan.,  1897-June,  1898;  Student  in  Phy- 
sics, Universities  of  Gottingen  and  Ber- 
lin,    1898-99 ;      Associate     in      Applied 


Published  Papers. 


563 


Mathematics  and  Physics,  Bryn  Mawr 
College,  1899-. 

Author  of :  — 

On  the  Susceptibility  of  Diamagnetic  and 
weakly  Magnetic  Substances.  Philo- 
sophical Magazine,  May,  1898,  5th 
ser..  Vol.  45,  pp.  432-447  ;  also  Physi- 
cal Bevieio,  April,  1898,  Vol.  6,  pp. 
223-238. 

Moleculare  Susceptibilitat  paramagneti- 
scher  Salze.  (With  O.  Liebknecht.) 
Verhandl.  cler  dents,  physik.  Gesell- 
schaft,  Sitz.  vom  30  Juni,  1899  (to  be 
published  later  in  extenso). 
Zur  thermometrischen  und  kryogenen  Ver- 
wendung  des  Kohlensaureschnees. 
(With  H.  du  Bois.)  Verhandl.  der 
dents,  physik.  Gesellschaft.  Sitz.  vom 
30  Juni,  1899.  (To  be  published  later 
in  extenso.) 

On  the  Magnetic  Shielding  Effect  of  Tri- 
lamellar  Spherical  and  Cylindrical 
Shells.  Physical  Review,  Oct.,  1899. 
Vol.  9,  pp.  193-213. 

MINOSUKE  Y AMAGUCHI : — 

LL.B.,  Tokio  Law  School,  1892  ;  Student 
in  Philosophy,  De  Pauw  University,  1894- 
97;  A.B.,  Lombard  University,  1897; 
Scholar  in  Psychology,  Clark  Univer- 
sity, 1897-98  ;  Graduate  Student,  Yale 
University,  1898-99. 

ALBERT   H.    YODER  : — 

Teacher  in  Public  Schools,  Dakota,  1882- 
87 ;  Graduate,  State  Normal  School, 
Madison,  So.  Dak.,  1888  ;  Superintendent 
of  Schools,  ibid.,  1888-91  ;  A.B.,  Univer- 
sity of  Indiana,  1893  ;  Scholar  in  Peda- 
gogy, Clark  University,  1893-94 ; 
Principal,  San  Francisco  Normal  School, 
1894-95  ;  Scholar  in  Psychology,  Univer- 
sity of  Chicago,  1895-9G ;  Specialist  in 
Pediatrics,  Northwestern  L^niversity  Medi- 
cal School,  1896  ;  President  of  the  Faculty 
and  Professor  of  Philosophy  and  Peda- 
gogy, Vincennes  University,  1896- ;  Edi- 
tor of  the  Bulletin  of  the  Preparatory 
Teachers'  Department,  Vincennes  Univer- 
sity, Nov.  1896-. 


Author  of :  — 

The  Study  of  the  Boyhood  of  Great  Men. 

Pedagogical  Seminary,  Oct.,  1894,  Vol. 

3,  pp.  134-156. 
A  Syllabus  for  the  Study  of  Pubescence. 

Child  Study  Monthly,  Feb.,  1896,  Vol. 

1,  pp.  280-282. 

Investigations  in  Pubescence.  Trans.  HI. 
Soc.  for  Child  Study,  1897,  Vol.  2,  No. 

2,  pp.  81-84. 

Pubescence.  Northwestern  Monthly,  May, 
1898,  Vol.  8,  pp.  597-600. 

LBW^IS   ED-WIN   YORK:  — 

Tutor  in  Mathematics,  Mt.  Union  College, 
1891-93  ;  B.S.,  Mt.  Union  College,  1894  ; 
Superintendent  of  Public  Schools,  Newton 
Falls,  O.,  1894-96  ;  Graduate,  King's 
School  of  Oratory,  1896  ;  President  Du- 
quesne  College,  1896-97;  Ph.D.  (i)ro 
merito),  Duquesne  College,  1897  ;  Scholar 
in  Pedagogy,  Clark  University,  1897- 
98 ;  Superintendent  Public  Schools, 
Kingsville,    O.,    1898-, 

Author  of :  — 

America's  Need  —  Men.     Plutocrat,  Oct., 

1893. 
Thoughts   on  Oratory.      Dynamo,   Jan., 

1895. 

J.    "W.    A.    YOUNG:  — 

A.B.,  Bucknell  University,  1887;  A.M., 
ihid.,  1890 ;  Instructor  in  Mathematics, 
Bucknell  Academy,  1887-88 ;  University 
of  Berlin,  1888-89 ;  Fellow  in  Mathe- 
matics, Clark  University,  1889-92  ; 
Ph.D.,  Clark  University,  1892  ;  Asso- 
ciate in  Mathematics,  University  of  Chi- 
cago, 1892-94;  Instructor  in  Mathematics, 
ibid.,  1894-97 ;  Assistant  Professor  of 
Mathematical  Pedagogy,  ibid.,  1897- ;  In- 
vestigating Methods  of  Teaching  Mathe- 
matics in  Prussia,  1897-98 ;  Member 
American  Mathematical  Society. 

Author  of :  — 

On  the  Determination  of  Groups  whose 
Order  is  a  Power  of  a  Prime.  Am. 
Jour,  of  Math.,  April,  1893,  Vol.  15, 
pp.  124-178. 


564 


Titles  of  Published  Papers. 


Bachmann's  Theory  of  Numbers.     Bull. 

N.  Y.  Math.  Soc,  June,  1894,  Vol.  3, 

pp.  215-222. 
Theory  of  Numbers  and   of  Equations. 

Bull.  Am.  Math.  Soc,  1896,  2d  ser., 

Vol.  3,  pp.  97-105. 
Zur    mathematischen    Lehrbticherf  rage : 

Eine   schulstatistische  Untersuchung. 


Hoffmann's  Zeits.  f.  math.  u.  natur- 
wiss.  Unterricht,  Sept.,  1898,  Vol.  29, 
pp.  410-414. 
The  Elements  of  the  Differential  and 
Integral  Calculus.  (With  C.  E.  Line- 
barger.)  D.  Appleton  &  Co.,  New 
York.     (In  press.) 


SPECIAL   STUDENTS   AND    MEMBERS   OF   THE 
SATURDAY   TEACHERS'    CLASS. 


[The  positions  here  specified  are  those  held  while  the  incumhents  were  connected  with  the 

University.] 


Allen,  Nellie  B.,  Instructor,  State  Normal  School,  Fitchburg,  Mass. 

Andrews,  Calvin  H.,  Instructor  in  Physics  and  Mathematics,  English  High  School,  Worcester, 

Mass. 
Andrews,  Walter  E.,  Instructor  in  Mathematics,  English  High  School,  Worcester,  Mass. 
Benneyan,  H.  G.,  Pastor,  Armenian  Congregational  Church,  Worcester,  Mass. 
Boy  den,  Arthur  C,  Vice-Principal,  State  Normal  School,  Bridgewater,  Mass. 
Brown,  Anna  L.,  Instructor,  Northfield  Training  School,  East  Northfield,  Mass. 
Buck,  Jonathan  I.,  Principal,  High  School,  Webster,  Mass. 

Calkins,  Mary  Whiton,  Assistant  Professor  of  Philosophy,  Wellesley  College,  Wellesley,  Mass. 
Carroll,  Clarence  F.,  Superintendent  of  Schools,  Worcester,  Mass. 
Casey,  Daniel  H.,  Principal,  Grafton  Street  School,  Worcester,  Mass. 
Childs,  Anne  Gertrude,  Instructor,  State  Normal  School,  Oneonta,  N.  Y. 
Clinton,  Mrs.  C.  W.  (Candidate  for  A.B.,  University  of  Minnesota),  Worcester,  Mass. 
Cole,  George  F. ,  Instractor  in  Modern  Languages,  English  High  School,  Worcester,  Mass. 
Colvin,  Stephen  S.,  Instructor  in  English,  English  High  School,  Worcester,  Mass. 
Dean,  Harold  M.,  Sub-master,  High  School,  Webster,  Mass. 
Defendorf,  Allen  P.,  Interne  at  Worcester  Insane  Hospital,  Worcester,  Mass. 
Delano,  Charles  W.,  Instructor,  Classical  High  School,  Worcester,  Mass. 
Drake,  Mary  A.,  Principal,  Washington  Street  Scliool, Worcester,  Mass. 
p]dmund,  Gertrude,  Principal,  Training  School,  Lowell,  Mass. 
Fish,  Rachel  C,  Instructor,  The  Dalzell  School,  Worcester,  Mass. 
Flagg,  Edward  W.,  Instructor  in  English,  State  Normal  School,  Potsdam,  N.  Y. 
Goodwin,  Edward  R.,  Principal,  Classical  High  School,  Worcester,  Mass. 
Gray,  Albert,  Instructor  in  Greek  History,  English  High  School,  Worcester,  Mass. 
Grout,  Edgar  H.,  Principal,  High  School,  Nqrth  Brookfield,  Mass. 

tHale,  Abby  C,  Teacher,  Downing  Street  School,  Worcester,  Mass.     Died,  May  1,  1899. 
Hale,  Edward  B.,  Principal,  High  School,  Brookfield,  Mass. 
Halsey,  Lila  S.,  Principal,  Northfield  Training  School,  East  Northfield,  Mass. 
Hamlin,  Alice  J.  (A.B.,  Wellesley  College),  Lexington,  Mass. 
Hanson,  Charles  L.,  Instructor,  English  High  School,  Worcester,  Mass. 
Haskell,  Ellen  M.,  Instructor,  State  Normal  School,  Worcester,  Mass. 
Hayes,  Grace  L.,  Principal,  Training  School,  Beverly,  Mass. 
Hill,  Gershom  H.,  Superintendent,  Iowa  Hospital,  Independence,  la. 

Howard,  Ervin  W.,  Assistant  in  Physics,  Worcester  Polytechnic  Institute,  Worcester,  Mass. 

565 


566  Special  Students. 

Howes,  Bessie  E.,  Assistant  Superintendent  of  Scliools,  Worcester,  Mass. 

Hunt,  Charles  L.,  Superintendent  of  Schools,  Clinton,  Mass. 

Ignatios,  A.  Marderos,  Smyrna,  Turkey. 

Irving,  Arthur  P.,  Superintendent  of  Schools,  Ayer  and  West  Boylston,  Mass. 

Jenkins,  James,  Principal,  English  High  School,  Worcester,  Mass. 

Judkins,  C.  L.,  Principal  High  School,  Oxford,  Mass. 

Kempfer,  J.  F.,  Worcester,  Mass. 

Keyes,  Charles  H.,  Principal,  High  School,  Holyoke,  Mass. 

Kimball,  Albert  B.,  Instructor  in  Physics,  English  High  School,  Worcester,  Mass. 

Lindley,  Mrs.  E.  H.  (A.B.,  Indiana  University),  Bloomington,  Ind. 

Lyman,  C.  S.,  Superintendent  of  Schools,  Oxford,  Mass. 

Miles,  Caroline,  Instructor  in  Psychology,  Wellesley  College,  Wellesley,  Mass. 

Mix,  Grace  E. ,  Teacher,  Salisbury  Street  Kindergarten,  Worcester,  Mass. 

Monroe,  Will  S.,  Instructor  In  Psychology  and  Pedagogy,  State  Normal  School,  Westfield, 

Mass. 
Naruse,  Jinzo,  Christian  Ministry,  Yaraaguchi,  Japan. 

Nelson,  William,  Graduate  Student,  Worcester  Polytechnic  Institute,  Worcester,  Mass. 
Olin,  Arvin  S.,  Superintendent  of  Schools,  Kansas  City,  Kansas. 
Phelon,  Joseph  O.,  Instructor  in  Physics  and  Electrical  Engineering,  Worcester  Polytechnic 

Institute,  Worcester,  Mass. 
Pitman,  J.  Asbury,  Superintendent  of  Schools,  West  Boylston  District,  Mass. 
Rice,  Arthur  L.,  Instructor  in  Mechanical  Engineering,  Worcester  Polytechnic  Institute, 

Worcester,  Mass. 
Rust,  Annie  C,  Principal,  Kindergarten  Normal  School,  Worcester,  Mass. 
Search,  Preston  W.,  Superintendent  of  Schools,  Holyoke,  Mass. 
Smith,  Clarissa  W.  (A.B.,  Bryn  Mawr  College),  Worcester,  Mass. 

Smith,  Clayton  0.,  Assistant  in  Physics,  Worcester  Polyteclinic  Institute,  Worcester,  Mass. 
Smith,  Ella  L.,  Instructor,  Classical  High  School,  Worcester,  Mass. 
Smith,  Rev.  H.  W.,  Universalist  Ministry,  Worcester,  Mass. 
Smith,  Preston,  Science  Teacher,  State  Normal  School,  Fitchburg,  Mass. 
Smith,  Theodate  L.  (Candidate  for  Ph.D.,  Yale  University),  New  Haven,  Conn. 
Southgate,  Hugh  M.,  Assistant  in  Physics,  Worcester  Polytechnic  Institute,  Worcester,  Mass. 
Stoddard,  George  H.,  Principal,  High  School,  East  Douglas,  Mass. 
Thompson,  Rev.  W.  J.,  Pastor,  Grace  j\I.  E.  Church,  Worcester,  Mass. 
Trumbull,  Mary,  Instructor,  English  High  School,  Worcester,  Mass. 
Viets,  Emily  H.,  Teacher,  Salisbury  Street  Kindergarten,  Worcester,  Mass. 
Waggener,  W.  J.,  Professor  of  Natural  Philosophy,  State  University  of  Colorado,  Boulder,  Col. 
Watts,  W.  G.,  Student  in  Biology,  Worcester,  Mass. 
Wilmarth,  Elmar  H.,  Instructor,  Manual  Training  High  School,  Worcester,  Mass. 


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